a) To express ∂z/∂u and ∂z/∂v as functions of u and v, we first need to express z directly in terms of u and v. We are given that:
z = tan^-1(x/y)
And that:
x = ucosv
y = usinv
Substituting these expressions for x and y into the equation for z, we get:
z = tan^-1((ucosv)/(usinv))
z = tan^-1(cotv)
Now we can use the chain rule to find ∂z/∂u and ∂z/∂v:
∂z/∂u = ∂z/∂cotv * ∂cotv/∂u
∂z/∂v = ∂z/∂cotv * ∂cotv/∂v
To find ∂cotv/∂u and ∂cotv/∂v, we use the quotient rule:
∂cotv/∂u = -cosv/u^2
∂cotv/∂v = -csc^2v
Substituting these into the chain rule expressions, we get:
∂z/∂u = (-cosv/u^2) * (1/(1+cot^2v))
∂z/∂v = (-csc^2v) * (1/(1+cot^2v))
Simplifying these expressions using trig identities, we get:
∂z/∂u = (-cosv/u^2) * (1/(1+(cosv/usinv)^2))
∂z/∂v = (-1/sinv^2) * (1/(1+(cosv/usinv)^2))
b) To evaluate ∂z/∂u and ∂z/∂v at (u,v) = (1.3, pi/6), we simply plug in these values into the expressions we derived in part (a):
∂z/∂u = (-cos(pi/6)/(1.3)^2) * (1/(1+(cos(pi/6)/(1.3*sin(pi/6)))^2))
∂z/∂v = (-1/sin(pi/6)^2) * (1/(1+(cos(pi/6)/(1.3*sin(pi/6)))^2))
Simplifying these expressions using trig functions, we get:
∂z/∂u = (-sqrt(3)/1.69^2) * (1/(1+(sqrt(3)/1.3)^2))
∂z/∂v = (-4) * (1/(1+(sqrt(3)/1.3)^2))
Plugging in the values and evaluating, we get:
∂z/∂u ≈ -0.5167
∂z/∂v ≈ -1.5045
To answer this question, we'll first express z directly in terms of u and v, and then apply the chain rule to find the partial derivatives ∂z/∂u and ∂z/∂v.
Given:
z = tan^(-1)(x/y)
x = u*cos(v)
y = u*sin(v)
First, let's express z in terms of u and v:
z = tan^(-1)((u*cos(v))/(u*sin(v)))
Now, we can simplify the expression:
z = tan^(-1)(cot(v))
Next, we'll find the partial derivatives using the chain rule:
a) ∂z/∂u:
Since z doesn't have a direct dependence on u, we have:
∂z/∂u = 0
b) ∂z/∂v:
∂z/∂v = -csc^2(v)
Now let's evaluate the partial derivatives at the given point (u,v) = (1.3, π/6):
∂z/∂u(1.3, π/6) = 0
∂z/∂v(1.3, π/6) = -csc^2(π/6) = -4
So, the partial derivatives at the given point are:
∂z/∂u = 0 and ∂z/∂v = -4.
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In an isosceles triangle, the measure of a base angle is 65. Find the number of degrees in the measure of the vertex angle
The number of degrees in the measure of the vertex angle is 50 degrees.
An isosceles triangle has two equal sides and two equal base angles. In your question, the measure of a base angle is 65 degrees. To find the measure of the vertex angle, we'll use the fact that the sum of angles in any triangle is always 180 degrees.
Since both base angles are equal, their combined measure is 2 * 65 = 130 degrees. Now, we subtract the sum of the base angles from the total angle measure of the triangle:
180 degrees (total angle measure) - 130 degrees (sum of base angles) = 50 degrees.
So, the measure of the vertex angle in the isosceles triangle is 50 degrees. In summary, when given the measure of a base angle in an isosceles triangle, we can use the triangle's angle sum property to find the measure of the vertex angle.
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Sarah has a solid wooden cube with a length of 4/5 cm. From each of its 8 corners, she cuts out a smaller cube with a length of 1/5 cm. What is the volume of the block after cutting out the smaller cubes?
The volume of the block after cutting out the smaller cubes is 56/125 cubic centimeters.
The initial volume of the solid wooden cube is given by:
V_initial = (4/5 cm)³ = 64/125 cm³
To find the volume of each of the 8 smaller cubes cut out from the corners, we can use the formula:
V_small cube = (1/5 cm)³= 1/125 cm³
Since we cut out 8 smaller cubes, the total volume of the smaller cubes is:
V_small cubes = 8 x (1/125 cm³) = 8/125 cm³
To find the final volume of the block after cutting out the smaller cubes, we can subtract the volume of the smaller cubes from the initial volume of the block:
V_final = V_initial - V_small cubes
Substituting the values we obtained earlier, we get:
V_final = (64/125 cm³) - (8/125 cm³) = 56/125 cm³
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Let AX = B be a consistent linear system with 12 equations and 8 variables. If the solution of the system contains 3 free variables, then what is the rank of the coefficient matrix A?
The rank of the coefficient matrix A is 5.
How to determined the matrix?Since the system AX = B is consistent and has 12 equations and 8 variables, the rank of the coefficient matrix A must be less than or equal to 8 (the number of variables).
If the solution of the system contains 3 free variables, it means that the dimension of the null-space of A is 3. By the rank-nullity theorem,
we know that the dimension of the null-space of A plus the rank of A is equal to the number of columns of A (which is 8 in this case).
Therefore, we have:
rank(A) + dim(null(A)) = 8
rank(A) + 3 = 8
rank(A) = 5
So, the rank of the coefficient matrix A is 5.
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A jury of 6 persons was selected from a group of 20 potential jurors, of whom 8 were african american and 12 were white. the jury was supposedly randomly selected, but it contained only 1 african american member. a) do you have any reason to doubt the randomness of the selection
Yes, there is reason to doubt the randomness of the jury selection based on the information provided.
Given data:
Out of the 20 potential jurors, 8 were African American and 12 were white. The probability of randomly selecting an African American juror from the pool of potential jurors would ideally be 8/20, which simplifies to 2/5 or 40%. However, the actual jury selected had only 1 African American member out of 6 jurors, which is significantly lower than the expected 40% if the selection were truly random.
This deviation from the expected probability raises questions about the randomness of the selection process. The observed outcome appears to be disproportionately skewed against the representation of African American jurors. While random variations can occur, the extent of the deviation in this case warrants further investigation into the jury selection process to determine if there were any biases or factors influencing the outcome.
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simple interest earned for principal of $2000 at and 8% rate for 5 years
Simple Interest is equal to ($800) (2000 x 8 x 5) / 100. The simple interest earned is therefore $800.
What is interest?The measure of cash returned or earned over a set period of time on a principal sum of money is referred to as interest. It is frequently stated as a share of the principal sum and it may be either simple or complicated. Compounding interest is computed on the principal amount as well as any accrued but unpaid interest, whereas simple interest is assessed just on the principal amount. Loans, investments, and bank deposits frequently include interest.
given
We can use the following calculation to determine the simple interest received for a $2000 principal at an 8% rate over a 5-year period:
S.I = (Principal x Rate x Time)/100
In this instance, Principal is $2000, Rate is 8% annually, and Term is 5 years.
With these values entered into the formula, we obtain:
Simple Interest is equal to ($800) (2000 x 8 x 5) / 100. The simple interest earned is therefore $800.
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A floor plan of a house was drawn using a scale of 1 inch:5 feet. if the kitchen is drawn 2 1/2 inches by 3 inches, what are the dimensions of the actual kitchen?
If the kitchen is drawn 2 1/2 inches by 3 inches, the actual dimensions of the kitchen are 12.5 feet by 15 feet.
The given scale of 1 inch:5 feet means that for every 1 inch on the floor plan, the actual length in real life is 5 feet. To find the actual dimensions of the kitchen, we need to convert the length and width of the kitchen on the floor plan into real-life measurements.
The length of the kitchen on the floor plan is 2 1/2 inches, which in real life would be:
2.5 inches x 5 feet/1 inch = 12.5 feet
Similarly, the width of the kitchen on the floor plan is 3 inches, which in real life would be:
3 inches x 5 feet/1 inch = 15 feet
To verify this result, we can also use the scale to convert the actual dimensions of the kitchen back into the measurements on the floor plan. The length of the kitchen in real life is 12.5 feet, which on the floor plan would be:
12.5 feet x 1 inch/5 feet = 2.5 inches
Similarly, the width of the kitchen in real life is 15 feet, which on the floor plan would be:
15 feet x 1 inch/5 feet = 3 inches
As expected, these measurements match the dimensions of the kitchen as drawn on the floor plan.
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50 PONTS Triangle LMN has vertices at L(−1, 4), M(−1, 0), and N(−3, 4) Determine the vertices of image L′M′N′ if the preimage is rotated 90° clockwise about the origin.
L′(4, 1), M′(0, 1), N′(4, 3)
L′(−1, −4), M′(−1, 0), N′(−3, −4)
L′(−4, −1), M′(0, −1), N′(−4, −3)
L′(1, −4), M′(1, 0), N′(3, −4)
The coordinates of the resulting triangle are L'(4, 1), M'(0, 1), and N'(4, 3)
What are the coordinates of the resulting triangle?From the question, we have the following parameters that can be used in our computation:
Triangle LMN has vertices at L(−1, 4), M(−1, 0), and N(−3, 4
This means that
L(−1, 4), M(−1, 0), and N(−3, 4Rotation rule = 90° clockwise around the origin.The rotation rule of 90° clockwise around the origin is
(x,y) becomes (y,-x)
So, we have
Image = (y, -x)
Substitute the known values in the above equation, so, we have the following representation
L'(4, 1), M'(0, 1), and N'(4, 3)
Hence, the coordinates of the resulting points, are L'(4, 1), M'(0, 1), and N'(4, 3)
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Answer:L′(4, 1), M′(0, 1), N′(4, 3)
Step-by-step explanation:
I am in the middle of taking the quiz and I believe this is the correct answer!
Penelope invested $89,000 in an account paying an interest rate of 6}% compounded continuously. Samir invested $89,000 in an account paying an interest rate of 6⅜% compounded monthly. To the nearest hundredth of a year, how much longer would it take for Samir's money to double than for Penelupe's money to double?
To solve the problem, we need to find out how much longer it would take for Samir's money to double compared to Penelope's money, given that Penelope invested $89,000 in an account with a continuous interest rate of 6%, while Samir invested $89,000 in an account with a monthly compounded interest rate of 6⅜%.
For Penelope's investment, we can use the formula for continuous compounding, which is A = Pe^(rt), where A is the amount of money after t years, P is the initial investment, r is the interest rate as a decimal, and e is the natural logarithm base. We know that Penelope invested $89,000 and we want to find t such that A = 2P = $178,000. Thus, we have:
$178,000 = $89,000e^(0.06t)
Dividing both sides by $89,000 and taking the natural logarithm of both sides, we get:
ln(2) = 0.06t
Solving for t, we get:
t = ln(2)/0.06 ≈ 11.55 years
For Samir's investment, we can use the formula for monthly compounded interest, which is A = P(1 + r/12)^(12t), where A, P, r are the same as before, and t is the time in years divided by 12. Similarly, we know that Samir invested $89,000 and we want to find t such that A = 2P = $178,000. Thus, we have:
$178,000 = $89,000(1 + 0.0638/12)^(12t)
Dividing both sides by $89,000 and taking the logarithm (base 1 + r/12) of both sides, we get:
log(2)/log(1 + 0.0638/12) = 12t
Solving for t, we get:
t ≈ 11.80/12 = 0.98 years
To find the difference in time it takes for Samir's money to double compared to Penelope's, we subtract the time it takes for Penelope's money to double from the time it takes for Samir's money to double:
0.98 - 11.55 ≈ -10.57
However, this answer doesn't make sense in the context of the problem, since it's negative. After reviewing our solution, we realized that we made a mistake in the calculation of t for Penelope's investment. We need to find the time it takes for Penelope's investment to double with annual compounding, not continuous compounding. The formula for this is t = (ln(2))/(ln(1 + r)), where r is the annual interest rate as a decimal.
Plugging in the numbers, we get:
t = (ln(2))/(ln(1 + 0.06)) ≈ 11.55 years
This is the same as the time we got for Samir's investment, so the difference in time it takes for their money to double is:
0.98 - 11.55 ≈ -10.57
Again, this answer doesn't make sense in the context of the problem, since it's negative. Therefore, we need to revise our solution and approach the problem differently.
Mike receives a bonus every year. His bonus is calculated as 3 percent of his company's total profits. If he estimates his company's total profits to be between $500,000 and $650,000, which inequality best represents Mike's bonus, B, for the year?
Mike's bonus for the year is between $15,000 and $19,500.
The inequality that best represents Mike's bonus, B, for the year is:
$15,000 [tex]\leq B \leq[/tex] 19,500$
to see why, we are able to use the given data that Mike's bonus is calculated as 3 percent of his corporation's overall profits.
If we let P be the organization's general income, then Mike's bonus B can be expressed as:
$B = 0.03P$
We recognise that the organization's total profits are between $500,000 and $650,000, so we will write:
$500,000 [tex]\leq P \leq[/tex] 650,000$
Substituting this inequality into the equation for Mike's bonus, we get:
$15,000 [tex]\leq B \leq[/tex] 19,500$
Therefore, Mike's bonus for the year is between $15,000 and $19,500.
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Drag each tile to its equivalent measure, rounded to the nearest tenth.
19. 810. 222. 715. 4
Measure Equivalent
4 in.
cm
7 kg
lb
6 gal
L
65 ft
m
The given value of 19 is not a unit of measurement, so it cannot be converted to an equivalent measure.
How to drag each tile to its equivalent measure, rounded to the nearest tenth?4 in. - 10.2 cm
7 kg - 15.4 lb
6 gal - 22.7 L
5 ft - 1.5 m
Note: The given value of 19 is not a unit of measurement, so it cannot be converted to an equivalent measure.
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SOMEONE HELP!! giving brainlist to anyone who answers
Answer:
We can use the Pythagorean theorem to find the length of the third side of the triangle ABC:
AB^2 = AC^2 + BC^2
(29)½^2 = 5^2 + 2^2
29 = 25 + 4
29 = 29
So the triangle is a right triangle with angle A being the angle opposite the side AC. Therefore, we can use the tangent function to find tan A:
tan A = opposite/adjacent = AC/BC = 5/2
So the exact value of tan A is 5/2.
Find the area of the regular polygon. Round your answer to the nearest whole number of square units.
The area is about square units.
The area of the regular pentagon is about 9 square units.
To find the area of a regular polygon, we need to know the length of the apothem and the perimeter of the polygon. The apothem is the distance from the center of the polygon to the midpoint of one of its sides, and the perimeter is the sum of the lengths of all the sides.
Since the polygon is regular, all of its sides have the same length. Let's call that length "s". We also know that the polygon has 5 sides, so it is a pentagon. To find the perimeter, we can simply multiply the length of one side by the number of sides:
Perimeter = 5s
Now, to find the apothem, we can use the formula:
Apothem = (s/2) x tan(180/n)
Where "n" is the number of sides. For our pentagon, n = 5, so we have:
Apothem = (s/2) x tan(36)
We can simplify this a bit by noting that tan(36) is equal to approximately 0.7265. So we have:
Apothem = (s/2) x 0.7265
Now we have everything we need to find the area. The formula for the area of a regular polygon is:
Area = (1/2) x Perimeter x Apothem
Substituting in the values we found earlier, we have:
Area = (1/2) x 5s x (s/2) x 0.7265
Simplifying this expression, we get:
Area = (s^2 x 1.8176)
Rounding to the nearest whole number of square units, we have:
Area = 9
So the area of the regular pentagon is about 9 square units.
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How do I take a picture
To take a picture we must press the shutter button pointing the lens towards the image we want to capture.
How to take a picture?To take a picture we must follow the following steps. In general, we must have a camera at hand and know how to use it. There is a great diversity of cameras with different characteristics, but the basics to take a photo are the following:
In the first place, we must locate ourselves at a prudent distance from the element that we are going to photograph, making sure that it comes out completely in the camera's focus.
Once we have focused on the object, we must make sure that nothing is going to move the camera or go through between the camera and the object.
Later, we must make sure that there is enough light for the object to come out sharp in the photo.
Finally, we press the shutter and take the photo. In some cases we will have the digital photo or in others we will be able to print it on photographic paper.
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Lisa has 9 rings in her jewelry box. Five are gold and 4 are silver. If she randomly selects 3 rings to wear to a party, find each probability. P(2 silver or 2 gold)
The probability of selecting 2 silver rings or 2 gold rings is 3/28.
How to find the probability of selecting 2 silver rings or 2 gold rings?To find the probability of selecting 2 silver rings or 2 gold rings, we need to find the probability of each event separately and then add them.
Probability of selecting 2 silver rings:
There are 4 silver rings out of 9 total, so the probability of selecting a silver ring on the first draw is 4/9. After the first ring is selected, there are 3 silver rings left out of 8 total, so the probability of selecting a second silver ring is 3/8. Finally, after two silver rings have been selected, there are 2 silver rings left out of 7 total, so the probability of selecting a third silver ring is 2/7. Therefore, the probability of selecting 2 silver rings is:
(4/9) * (3/8) * (2/7) = 24/504 = 1/21
Probability of selecting 2 gold rings:
Similarly, there are 5 gold rings out of 9 total, so the probability of selecting a gold ring on the first draw is 5/9. After the first ring is selected, there are 4 gold rings left out of 8 total, so the probability of selecting a second gold ring is 4/8 = 1/2. Finally, after two gold rings have been selected, there are 3 gold rings left out of 7 total, so the probability of selecting a third gold ring is 3/7. Therefore, the probability of selecting 2 gold rings is:
(5/9) * (1/2) * (3/7) = 15/126 = 5/42
Adding the probabilities of selecting 2 silver rings or 2 gold rings, we get:
P(2 silver or 2 gold) = P(2 silver) + P(2 gold) = 1/21 + 5/42 = 3/28
Therefore, the probability of selecting 2 silver rings or 2 gold rings is 3/28.
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A company knows that unit cost and unit revenue from the production and sale of x units are related by C. + 10621. Find the rate of change of revenue per unit when the 102.000 cost per unit is changing by $8 and the revenue is $4,000 O A $102.00 OD $160.00 OC. $577.05 OD. $1,052.10
The rate of change of revenue per unit is $8 when the unit cost is changing by $8 and the revenue is $4,000.
We are given that the unit cost (C) and unit revenue (R) are related by the equation C = R + 10621.
We want to find the rate of change of revenue per unit, dR/dx, when the unit cost (C) is changing by $8 per unit and the revenue (R) is $4,000.
1. Differentiate the given equation with respect to x: dC/dx = dR/dx
2. Plug in the given values: dC/dx = $8 (cost per unit is changing by $8) R = $4,000 (revenue per unit)
3. Solve for the cost per unit (C) using the equation
C = R + 10621
C = $4,000 + 10621
C = $14,621
4. Since dC/dx = dR/dx, and we know dC/dx = $8,
we can find the rate of change of revenue per unit (dR/dx) when the cost per unit is changing by $8: dR/dx = $8
Thus, the rate of change of revenue per unit is $8 when the unit cost is changing by $8 and the revenue is $4,000.
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What is the vertex and x-intercepts of -6x^2-50x+3085. 25
The vertex and x-intercepts of -6x^2-50x+3085. 25 are approximately -42.60 and 30.97.
To find the vertex and x-intercepts of the quadratic function -6x^2-50x+3085.25, we first need to express it in standard form -6x^2-50x+3085.25 = -6(x^2+8.33x-514.21)
So the x-intercepts are approximately -42.60 and 30.97.
We can complete the square to find the vertex of the parabola:
-6(x^2+8.33x-514.21) = -6[(x+4.165)^2-575.641]
-6(x^2+8.33x-514.21) = -6(x+4.165)^2+3453.844
So the vertex is at (-4.165, 575.844).
To find the x-intercepts, we can set y = 0 and solve for x:
-6x^2-50x+3085.25 = 0
Dividing both sides by -2.25 to simplify, we get:
2.6667x^2+22.2222x-1372.2222 = 0
Using the quadratic formula, we get:
x = (-22.2222 ± sqrt(22.2222^2-4(2.6667)(-1372.2222))) / (2(2.6667))
x = (-22.2222 ± sqrt(37511.1116)) / 5.3334
x = (-22.2222 ± 193.7262) / 5.3334
So the x-intercepts are approximately -42.60 and 30.97.
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The equation of the line of best fit for the exam grade per hour studied is
y = 6x + 60. What is the residual for 1 hours of studying?
The predicted exam grade for 1 hour of studying is 66. Therefore the residual for 1 hours of studying can be calculated as Residual = Actual Exam Grade - 66.
To find the residual for 1 hour of studying, we first need to determine the predicted exam grade and compare it to the actual exam grade for that specific data point.
Using the line of best fit equation y = 6x + 60, we can find the predicted exam grade for 1 hour of studying:
y = 6(1) + 60
y = 6 + 60
y = 66
So, the predicted exam grade for 1 hour of studying is 66. To calculate the residual, you need the actual exam grade for 1 hour of studying. If that information is not provided, the residual cannot be calculated. If the actual grade is provided, subtract the predicted grade from the actual grade to find the residual:
Residual = Actual Exam Grade - Predicted Exam Grade
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Evaluate the repeated integral: lolla (-xy + 2 z) dz dy dx a) O 15 b) 60 c) 30 d) 36 e) O72 f) O None of these.
The evaluation of the repeated integral is None of these. (option f)
The repeated integral given is ∫∫∫(-xy + 2z) dz dy dx over the region lolla. This means that you need to integrate the function (-xy + 2z) with respect to z, then with respect to y, and finally with respect to x over the region lolla.
To evaluate this integral, you can use the method of iterated integrals. First, integrate (-xy + 2z) with respect to z, treating x and y as constants:
∫∫(-xy + 2z) dz = -xyz + z² + C
where C is the constant of integration.
Next, integrate the result of the first integral with respect to y, treating x as a constant:
∫[-xyz + z² + C] dy = -xyz + y[-xyz + z² + C] + D
where D is the constant of integration.
Finally, integrate the result of the second integral with respect to x:
∫[-xyz + y(-xyz + z² + C) + D] dx = (-1/2) x² yz + xy(-xyz + z² + C) + Dx + E
where E is the constant of integration.
Now, you need to evaluate this expression over the region lolla. Without further information about the limits of integration for each variable, it is not possible to determine the exact value of this integral.
Therefore, the correct answer is f) None of these.
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Solve the equation and justify each step.
p - 4 = -9 + p
Answer: 0= -5
Step-by-step explanation:
Use 40, 37, 30, 40, 39, 41, 38, n.
1. If the mean was 43, n = ____
2. If the mean was 40, n = ____
3. If the mean was 38, n = ____
Answer:
[tex]40 + 37 + 30 + 40 + 39 + 41 + 38 + n = 265 + n[/tex]
1)
[tex] \frac{265 + n}{8} = 43[/tex]
[tex]265 + n = 344[/tex]
[tex]n = 79[/tex]
2)
[tex] \frac{265 + n}{8} = 40[/tex]
[tex]265 + n = 320[/tex]
[tex]n = 55[/tex]
3)
[tex] \frac{265 + n}{8} = 38[/tex]
[tex]265 + n = 304[/tex]
[tex]n = 39[/tex]
Qn in attachment
.
..
Answer:
option a
Step-by-step explanation:
it is the formula for varience.
CAN SOMEONE PLEASE HELP ME ILL GIVE BRAINLIST
Mai and Elena are shopping
for back-to-school clothes. They found a skirt that originally cost $30
on a 15% off sale rack. Today, the store is offering an additional 15% off. To find the new price of
the skirt, in dollars, Mai says they need to calculate 30. 0. 85 0. 85. Elena says they can just
multiply 30. 0. 70.
1. How much will the skirt cost using Mai's method?
2. How much will the skirt cost using Elena's method?
3. Explain why the expressions used by Mai and Elena give different prices for the skirt. Which
method is correct?
1. The skirt cost using Mai's method is $21.68.
2. The skirt cost using Elena's method is $21.
3. Mai's method is correct because she correctly calculates the discounts sequentially while Elena combines the discount.
We'll examine the methods suggested by Mai and Elena for finding the new price of the skirt and determine which one is correct.
1. Using Mai's method (30 x 0.85 x 0.85):
1: Calculate the first 15% off discount: 30 x 0.85 = 25.50
2: Calculate the additional 15% off discount: 25.50 x 0.85 = 21.675
So, the skirt will cost $21.68 using Mai's method (rounded to the nearest cent).
2. Using Elena's method (30 x 0.70):
Elena suggests taking 30% off the original price. To do this, we multiply the original price by 0.70:
30 x 0.70 = 21
So, the skirt will cost $21 using Elena's method.
3. Explanation of the difference in expressions and the correct method:
Mai's method is correct because she correctly calculates the discounts sequentially. The first 15% off is applied to the original price, and then the additional 15% off is applied to the reduced price. This results in a final price of $21.68.
Elena's method is incorrect because she combines the two discounts into a single 30% off, which does not accurately reflect the sequential discounts. By doing this, she finds a final price of $21, which is not correct.
In conclusion, Mai's method (30 x 0.85 x 0.85) is the correct way to calculate the new price of the skirt, resulting in a final cost of $21.68.
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Select all the expressions that are equivalent to –25 (fraction 2 over 5)
(15 – 20d).
The equivalent expressions are,
A. [tex]-30 + 40d - 10c[/tex],
B. [tex]-6 + 8d - 2c[/tex]
D. [tex]6 - 8d + 2c[/tex].
What are expressions?An expression is a sentence with at least two numbers or variables having mathematical operation. Math operations can be addition, subtraction, multiplication, division.
For example, [tex]2x+3[/tex]
The given expression.
[tex]\implies -25(15 - 20d + 5c)[/tex]
[tex]\implies -125(3 - 4d + c)[/tex]
So, the given expression can be converted into
[tex]k(3 - 4d + c)[/tex]
The equivalent expressions are:
A. [tex]-30 + 40d - 10c[/tex],
B. [tex]-6 + 8d - 2c[/tex]
D. [tex]6 - 8d + 2c[/tex].
A. [tex]-30 + 40d - 10c[/tex]
[tex]\implies -30 + 40d - 10c[/tex]
[tex]\implies -10(3 - 4d + c)[/tex]
B. [tex]-6 + 8d - 2c[/tex]
[tex]\implies -6 + 8d - 2c[/tex]
[tex]\implies -2(3 - 4d + c)[/tex]
D. [tex]6 - 8d + 2c[/tex]
[tex]\implies6 - 8d + 2c[/tex]
[tex]\implies2(3 - 4d + c)[/tex]
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Some students were asked how many pens they were carrying in their backpacks. The data is given in this frequency table. What is the mean number of pens carried by these students in their backpacks?
A. 2
B. 3. 5
C. 4
D. 5. 5
The mean number of pens carried by these students in their backpacks is:
122 / 30 = 4.07 (rounded to two decimal places)
So the answer is closest to option C, which is 4.
What is the mean number of pens carried by students in their backpacks given the following frequency table?To find the mean number of pens carried by the students, we need to calculate the sum of all the pens and divide by the total number of students. We can use the frequency table to calculate the sum of all the pens as follows:
2 x 3 + 3 x 6 + 4 x 10 + 5 x 8 + 6 x 3 = 6 + 18 + 40 + 40 + 18 = 122
The total number of students is the sum of the frequencies, which is:
3 + 6 + 10 + 8 + 3 = 30
The mean number of pens carried by these students in their backpacks is:
122 / 30 = 4.07 (rounded to two decimal places)
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Lines ab and cd are parallel. if 6 measures (4x - 31)°, and 5 measures 95°, what is the value of x? a. x = 19 b. x = 95 c. x = 265 d. x = 29
Answer: x=29
Step-by-step explanation:
To find the value of x, we can set the two angles equal to each other and solve for x, which gives x = 19.
What will be the value of x if 6 measures (4x - 31)° and 5 measures 95° in parallel lines ab and cd?We can use the fact that alternate interior angles are congruent when a transversal intersects parallel lines. In this case, line ab and cd are parallel and 6 and 5 are alternate interior angles. So we can set up an equation:
4x - 31 = 95
Solving for x:
4x = 126
x = 31.5
So the value of x is not one of the answer choices given. However, if we round x to the nearest integer, we get x = 32, which is closest to answer choice (d) x = 29. Therefore, the closest answer choice is (d) x = 29.
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What expression represents the volume of the cylinder, in cubic units? 4πx2 2πx3 πx2 2x 2 πx3
The expression that represents the volume of the cylinder, in cubic units, is:
[tex]$$V = 2\pi x^3$$[/tex]
The expression that represents the volume of a cylinder in cubic units is given by the formula:
[tex]$$V = \pi r^2h$$[/tex]
where [tex]$r$[/tex] is the radius of the base of the cylinder and [tex]$h$[/tex] is the height of the cylinder.
Now, let's consider each option provided:
[tex]1. $4\pi x^2$[/tex]
This expression only includes the radius, but it does not include the height of the cylinder, so it cannot be the correct answer.
[tex]2. $2\pi x^3$[/tex]
This expression includes both the radius and the height of the cylinder, but it does not include the squared term for the radius, so it cannot be the correct answer.
[tex]3. $\pi x^2$[/tex]
This expression includes the squared term for the radius, but it does not include the height of the cylinder, so it cannot be the correct answer.
[tex]4. $2x$[/tex]
This expression only includes a single variable, which is neither the radius nor the height of the cylinder, so it cannot be the correct answer.
[tex]5. $2\pi x^3$[/tex]
This expression includes both the squared term for the radius and the height of the cylinder, so it is the correct answer.
Therefore, the expression that represents the volume of the cylinder, in cubic units, is:
[tex]$$V = 2\pi x^3$$[/tex]
This formula can be used to calculate the volume of a cylinder given the value of its radius and height.
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Find the midpoint of the line segment joining (-4,-2) and (2,8) please show how u got your answer!!!
Answer:
(1,3)
Step-by-step explanation:
The midpoint formula is:
[tex](\frac{x1+x2}{2}),(\frac{y1+y2}{2})[/tex]
We have our 2 points, (-4,-2) and (2,8).
For this sake and for this explanation, point 1 is (-4,-2), and point 2 is (2,8).
We can substitute in our values:
[tex](\frac{-4+2}{2}),(\frac{-2+8}{2})[/tex]
substitute
[tex](\frac{2}{2}),(\frac{6}{2})[/tex]
Our midpoint is located at (1,3)
Hope this helps! :)
Answer:
(-1,3)
Step-by-step explanation:
To find the midpoint of a line segment, you want to find the change in x and y.
From (-4,-2) to (2,8), you move right by 6 and up by 10.
The midpoint is exactly half of this, meaning right by 3 and up by 5.
Therefore, the midpoint is (-1,3).
Determine the maximum profit if the marginal cost and marginal revenue are given by C'(x) = 20+ x/20 and R'(x) = 40 and fixed cost is $100.00.
The maximum profit is $3,900 if the marginal cost and marginal revenue are given by C'(x) = 20+ x/20 and R'(x) = 40 and fixed cost is $100.00.
In order to determine the maximum profit, we need to find the quantity (x) where the marginal cost (C'(x)) equals the marginal revenue (R'(x)). This is because when these two values are equal, we are maximizing the profit. The given functions are:
C'(x) = 20 + x/20
R'(x) = 40
First, set the marginal cost equal to the marginal revenue:
20 + x/20 = 40
Now, we need to solve for x:
x/20 = 40 - 20
x/20 = 20
x = 20 * 20
x = 400
So, the maximum profit occurs at a quantity of 400 units. To find the total cost (C(x)) and total revenue (R(x)), we need to integrate the marginal cost and marginal revenue functions:
C(x) = ∫(20 + x/20) dx = 20x + x^2/40 + C₁
R(x) = ∫40 dx = 40x + C₂
Since we have a fixed cost of $100, we know that C₁ = 100. We don't need C₂ to find the profit, as it will cancel out when we calculate it. Now, let's find the total cost and total revenue for 400 units:
C(400) = 20(400) + (400)^2/40 + 100 = 8000 + 4000 + 100 = 12100
R(400) = 40(400) = 16000
Finally, calculate the profit (P(x)):
P(x) = R(x) - C(x) = 16000 - 12100 = 3900
Therefore, the maximum profit is $3,900 when producing 400 units.
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1. Sally Rose's charge account statement showed a previous balance of $6,472. 82, a finance charge of $12. 95,
new purchases of $1,697. 08, and a payment of $4,900. 50. What is her new balance?
a. $3,454. 99
c. $3,566. 44
b. $3,282. 35
d. $3,112. 78
Sally Rose's new balance is $3,282.35, and option (b) is the correct answer.
Sally Rose's charge account statement contains information about her previous balance, finance charge, new purchases, and payment. To determine her new balance, we need to take the previous balance, add the finance charge and new purchases, and then subtract the payment.
Starting with the previous balance of $6,472.82, we add the finance charge of $12.95 and new purchases of $1,697.08 to get a total of:
$6,472.82 + $12.95 + $1,697.08 = $8,182.85
Next, we subtract the payment of $4,900.50 to get the new balance:
$8,182.85 - $4,900.50 = $3,282.35
It's important to keep track of credit card balances to avoid accumulating too much debt and paying high interest charges. When making credit card payments, it's a good idea to pay more than the minimum amount due, which can help reduce the balance faster and save money on interest charges over time. The answer is option b).
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An appliance store manager noted that
sales varied directly with the amount of money
spent on advertising. If last week's sales were
$10,000 and $2000 was spent on advertising,
what should sales be during a week that $1200
was spent on advertising?
In the given problem, solving systematically, sales should be $6,000 during a week that $1,200 was spent on advertising.
How to Calculate the Sales?If sales vary directly with the amount of money spent on advertising, it means that the ratio of sales to advertising spending is constant. We can use this ratio to find out what sales should be during a week that $1200 was spent on advertising.
Let the ratio of sales to advertising spending be denoted by k. Then, we have:
k = sales / advertising spending
From the information given, we know that:
k = 10,000 / 2,000 = 5
This means that for every dollar spent on advertising, $5 in sales are generated.
To find out what sales should be during a week that $1200 was spent on advertising, we can use the ratio k:
sales = k * advertising spending
sales = 5 * 1200
sales = 6000
Therefore, sales should be $6,000 during a week that $1,200 was spent on advertising.
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