Answer:
Step-by-step explanation:
How to calculate the area of an ellipse by using integration?
An ellipse has the general equation
(x/a)² + (y/b)² = 1
(actually, this is an ellipse whose semimajor and -minor axes are parallel to the x- and y-axes, but one can rotate any ellipse so that it has the same configuration, and the area remains constant)
Convert to a kind of rescaled polar coordinates, using
x = a r cos(t)
y = b r sin(t)
Then the interior of such an ellipse is the set
E = {(r, t) : 0 ≤ r ≤ 1 and 0 ≤ t ≤ 2π}
The area of E is then given by the integral
[tex]\displaystyle \iint_E dA[/tex]
Compute the Jacobian determinant for this change of coordinates. The Jacobian is
[tex]J = \begin{bmatrix}x_r & x_t \\ y_r & y_t\end{bmatrix} = \begin{bmatrix}a \cos(t) & -a r \sin(t) \\ b \sin(t) & b r \cos(t)\end{bmatrix}[/tex]
Then we have Jacobian determinant
|det(J)| = |a b r cos²(t) + a b r sin²(t)| = |a b r| = |a b| r
since r ≥ 0.
The area of E is then
[tex]\displaystyle \iint_E dA = \iint_E |ab| r \, dr \, dt[/tex]
[tex]\displaystyle \iint_E dA = \int_0^{2\pi} \int_0^1 |ab| r \, dr \, dt[/tex]
[tex]\displaystyle \iint_E dA = 2\pi |ab| \int_0^1 r \, dr[/tex]
[tex]\displaystyle \iint_E dA = \boxed{\pi |ab|}[/tex]
John’s grocery bill totaled $200. After he used his coupons, the cash register showed the total bill as $20. Which statement is true?
Answer:
90% off
Step-by-step explanation:
Your question is incomplete.
If these are the statement.. The answer is below:
The grocery bill before the coupons were used was 10 times as much as the bill after the coupons were used.
The grocery bill after the coupons were used was 10 times as much as the bill before the coupons were used.
The grocery bill before the coupons were used was 100 times as much as the bill after the coupons were used.
The grocery bill after the coupons were used was 100 times as much as the bill before the coupons were used.
Answer:
The grocery bill before the coupons were used was 10 times as much as the bill after the coupons were used.
Step-by-step explanation:
The price after coupons were used is $20, and the price before was $200. $20 · 10 =$200
Select the correct answer.
Which statement and reason best complete the proof?
Answer:
A. - This is my guess.
waiting for other questions
Answer:
A) 13
Step-by-step explanation:
If you recall the formula for finding a diagonal, or a^2 + B^2 = C^2, you will get 12^2 + 5^2 = C^2, if you solve that, you will get 13!
-2x + 4y -5 - 5x + 3y -9
Answer:
-7x + 7y - 14
Step-by-step explanation:
Please help me solve this ASAP!
Step-by-step explanation:
[tex] \frac{4.8}{1 \frac{7}{9} } = (1.2b) \div 6 \frac{2}{3} [/tex]
[tex] \frac{ \frac{48}{10} }{ \frac{16}{9} } = \frac{12b}{10} \div \frac{20}{3} [/tex]
[tex] \frac{48 \times 9}{10 \times 16} = \frac{12b}{10} \times \frac{3}{20} [/tex]
[tex] \frac{432}{160} = \frac{36b}{200} [/tex]
[tex]432 \times 200 = 160 \times 36b[/tex]
[tex]86400 = 5760b[/tex]
[tex]b = \frac{86400}{5760} [/tex]
[tex]b = 15[/tex]
What value is equivalent to 2 × 3 + 4 − 6^2?
A) -26
B) -22
C) -2
D) 10
Answer:
-26
Step-by-step explanation:
2 × 3 + 4 − 6^2
PEMDAS
exponents are first in this equation
2 × 3 + 4 − 36
Then multiply
6 +4 -36
Then add and subtract from left to right
10-36
-26
Answer:
A) -26
Step-by-step explanation:
2 * 3 + 4 - 6²
Use PEMDAS to figure out the equation.
Pass parenthesis since there are none in the equation.
Evaluate all of the exponents.
2 * 3 + 4 - 36
Evaluate all of the multiplication in the equation.
6 + 4 - 36
Pass division since there isn't any in the equation.
Evaluate all of the addition in the equation.
10 - 36
Evaluate all of the subtraction in the equation.
-26.
if 3x/4 - 13 = -9 then what is the value of x^2
subtract X from 3X minus one
The population of a nearby town dropped from 7,500 to 6,000 in one year.
What was the percent decrease in the town's population that year?
Group of answer choices
Answer:Possible Answers: 13.2%. 5.7%. 15.0%.
Step-by-step explanation:
HELP YALL PLEASE! I WILL MARK BRAINIEST TO WHOEVER IS CORRECT!!
Answer:
Line 1: Is parallel Line 2: Is Neither Line 3: Is parallel
What is the common ratio?
512, 256, 128, 64
Answer:
The constant factor between consecutive terms of a geometric sequence is called the common ratio. Example: To find the common ratio find the ratio between a term and the term preceding it. r=42=2. 2 is the common ratio.
Instructions: Find the measure of x and y.
R
89°
E
Х°
81°
G
yo
F
=
Y
Check
Answer:
m ∠x = 81° and m ∠y = 109°
Step-by-step explanation:
m ∠R = 1/2 (arc REG) m ∠G = 1/2(arc REF)
89° = 1/2 (arc REG) 81 = 1/2(arc REF)
178° = arc REG 162° = arc REF
m ∠x = 1/2 arc REF
m ∠x = 1/2( 162°)
m ∠x = 81° or m ∠G = m ∠x because these to angles intersect the same arc, therefore they are equal.
Now the polygon interior angles = 360° and you know the measure of three of the four angles, solve for the missing angle .
m ∠R + m ∠x + m ∠y + m ∠G = 360°
89° + 81° + m ∠y + 89° = 360°
(89 + 81 + 81) + m ∠y = 360°
251° + m ∠y = 360°
m ∠y = 109°
One number is one more than another. Their sum is nine. Find both numbers.
Answer:
4 and 5
Step-by-step explanation:
Let's make an equation to solve. Let's call "one number" x. Another number is 1 more than x, so now we have x + 1. x plus x + 1 is equal to 9... and this gives us our equation:
x + (x + 1) = 9
We can now simplify by adding like terms together:
2x + 1 = 9
Now, let's take away 1 from both sides:
2x = 8
We can finally divide both sides by 2 to isolate x:
x = 4
One of our numbers is 4. Our other number is one more than 4, and 4 + 1 = 5. So our numbers are 4 and 5.
Hopefully this was helpful! If you need more help, let me know.
Today everything at a store is on sale. The store offers a 20% discount.The regular price of a T-shirt is $22. What is the discount price?
Answer:
$17.60
Step-by-step explanation:
WILL GIVE BRAINLIEST!!!
Answer:
A) 115°
Step-by-step explanation:
if PQ || RS then those two angles are supplementary
astrophysicist Neil deGrasse Tyson once commented somehow its ok for people to chuckle about not being good at math. Yet if I said I never learned to read they'd say I was an illiterate dolt he was referring to the notion that it has become socially acceptable for people to say they are bad at math but it is unacceptable to say they are bad at reading
Answer:
Step-by-step explanation:
`
I need help ASAP please “f(x)= ?”
Step-by-step explanation:
just think - what does it mean to translate (shift) a graph upward by 5 units ?
does the graph change in its content ? no. all the functional result value (= y values or coordinates) are still calculated as before, BUT before marking them on the chart the y values are moved up by 5 units. that means they are increased by 5 (that is the only way to move something "up" on a coordinate grid).
so, in other words, f(x) is nothing else but h(x), but it increases the results of h(x) consistently by 5.
h(x) = 2x² + 4
f(x) = h(x) + 5 = 2x² + 4 + 5 = 2x² + 9
A right triangle \mathrm{ABC}ABC is shown.
What is cos AA?
Answer:
90
Step-by-step explanation:
I need help with surface area
Answer:
904.8 m²
Step-by-step explanation:
needed formulas:
surface of a circle: πr²
circumference of a circle: 2πr
The top and bottom are circles with radius 9, and surface π9² = 81π m²
The side is a rectangle of 2·π·9·7 long, so that is 126π m²
Brings the total to 81π + 81π + 126π = 288π ≈ 904.8 m²
Whats -5/3+ 2 1/3 please help i dont wanna failPLWASEEE
Step-by-step explanation:
[tex] = - \frac{5}{3} + 2 \frac{1}{3} [/tex]
[tex] = - \frac{5}{3} + \frac{7}{3} [/tex]
[tex] = \frac{2}{3} [/tex]
Answer:
[tex] \sf \frac{2}{3} [/tex]
Step-by-step explanation:
[tex] \sf = - \frac{5}{3} + 2 \frac{1}{3} [/tex]
[tex] \sf = 2 \frac{1}{3} - \frac{5}{3} [/tex]
[tex] \sf = \frac{7}{3} - \frac{5}{3} [/tex]
[tex] \sf = \frac{7 - 5}{3} [/tex]
[tex] \sf = \frac{2}{3} [/tex]
What is the measure of angles A, B and C in the given triangles?
Answer:
A = 103°; B = 77°; C = 46°
Step-by-step explanation:
A + 45° + 32° = 180°
A + 77° = 180°
A = 180° - 77°
A = 103°
A + B = 180°
103° + B = 180°
B = 180° - 103°
B = 77°
B + C + 57° = 180°
77° + 57° + C = 180°
134° + C = 180°
C = 180° - 134°
C = 46°
I hope I've helped you.
What’s the answer ?
Answer:
a. y = 3^x
yep
ype
pey
Answer:
a
Step-by-step explanation:
plug the points into the equations
3¹=3
3²=9
3³=27
3⁴=81
3⁵=243
these are all true equations, so the answer is a
Yallah yallah i dont understand!
Answer:
Option D is your answer.
Step-by-step explanation:
Remember that the x-values are the x coordinates and the y-values are the y coordinates in an ordered pair. Ordered pairs are written like this (x,y).
So for line r, you got (-6,4), (-3,0), and (0,-4).
But you only need two of these pairs to determine slope. Let's do that real quick, by using this formula. (Sorry if it's small)⤵⤵⤵
[tex] \frac{y _{2} - y _{1} }{x _{2} - x _{1} } [/tex]
We'll use (-6,4) and ( -3,0).
0 - 4 = -4
-3 - (-6) = -3 + 6 = 3
So slope of line r is -4/3.
Now we'll do the same for line s:
Ordered pairs = (-5,-4), (5,0), and (20,6)
We'll use (-5,-4) and (5,0).
0 - (-4) = 0 + 4 = 4
5 - (-5) = 10
So slope of line s is 4/10 or 2/5.
Now we got to find the option choice that has these as the slopes.
We'll turn each into slope-intercept form.
A)
- Subtract 4x on both sides to get
3y = -4x - 12, then divide 3 on both sides to get y = -4/3 x - 4.
- Subtract 2x on both sides to get
-5y = -2x + 10, then divide -5 on both sides to get y = 2/5 x - 2.
B)
- Add 4x on both sides to get
3y = 4x + 12, the divide 3 on both sides to get y = 4/3 x + 4.
- Subtract 2x on both sides to get
-5y = -2x - 10, divide -5 on both sides to get y = 2/5 x + 2.
C)
- Subtract 4x on both sides to get
-3y = -4x - 12, then divide -3 on both sides to get y = 4/3 x + 4.
- Add 2x on both sides to get
-5y = 2x + 10, then divide -5 on both sides to get y = -2/5 x -2.
D)
- Add 4x on both sides to get
-3y = 4x - 12, then divide -3 on both sides to get y = -4/3 x + 4.
- Add 2x on both sides to get
5y = 2x + 10, then divide 5 on both sides to get y = 2/5 x + 2.
After all that writing we can tell that D is our answer, because both -4/3 and 2/5 appear as slopes.
Sorry this may seem like a lot, but the process really isn't that hard. Hope this helps :)
Simone wrote that 2 + 5.8 = 6.
Use the drop-down menus to explain why 6 is incorrect.
Answer:
Greater than 2+5
students are encouraged to exercise at least 2 1/2 hours a week. Hector exercises about the same number of hours each week. during a 4 week period he exercises 11 1/2 hours. how many hours does he exercise per week?
Answer:
On average, he exercises 2.875 hours per week.
Step-by-step explanation:
Just do 11 1/2 (11.5) divided by 4, and you get your answer of 2.875 hours per week.
x+5y=-5 find x and y intercept
Answer:
x= (5,0) y= (0,1)
Step-by-step explanation:
is y-4x=9 linear or not linear. if yes, write in standard form
Answer:
Yes it is linear. Standard Form: 4x - y = -9
Step-by-step explanation:
Wages, income tax, and money management
Answer:
the answer is a
Step-by-step explanation:
the reason its a is because it just it
nine less than six times a number is at most 33