Answer:
δw/δr = 4π
δw/δθ = -8π
Step-by-step explanation:
Given the following functions
w = xy + yz + zx, x = r cosθ y = r sinθ, z = rθ where r = 4 and θ = π/2
We are to find δw/δr and δw/δθ
δw/δr = δw/δx•δx/δr + δw/δy•δy/δr + δw/δz•δz/δr
δw/δx = y+z
δx/δr = cosθ
δw/δy = x+z
δy/δr = sinθ
δw/δz = y+x
δz/δr = θ
Substitute the given values into the formula
δw/δr = (y+z)cosθ+(x+z)sinθ+(y+x)θ
Substitute the value of x, y and z in terms of theta into the resulting function
δw/δr = (y+z)cosθ+(x+z)sinθ+(y+x)θ
δw/δr = (rsinθ+rθ)cosθ+(rcosθ+rθ)sinθ+(rsinθ+rcosθ)θ
Substitute r = 4 and θ = π/2
δw/δr = (4sinπ/2+4π/2)cosπ/2+(4cosπ/2+4π/2)sinπ/2+(4sinπ/2+4cosπ/2)π/2
Note that cos π/2 = 0 and sinπ/2 = 1
δw/δr = (4+2π)(0)+(0+2π)(1)+(4(1)+4(0))π/2
δw/δr = 0+2π+4π/2
δw/δr = 2π+2π
δw/δr = 4π
For δw/δθ
δw/δθ = δw/δx•δx/δθ + δw/δy•δy/δθ + δw/δz•δz/δθ
δw/δx = y+z
δx/δθ = -rsinθ
δw/δy = x+z
δy/δθ =rcosθ
δw/δz = y+x
δz/δθ = r
Substitute the given values into the formula
δw/δθ = (y+z)-rsinθ+(x+z)rcosθ+(y+x)r
Substitute the value of x, y and z in terms of theta into the resulting function
δw/δθ = (y+z)-rsinθ+(x+z)rcosθ+(y+x)r
δw/δθ = (rsinθ+rθ)-rsinθ+(rcosθ+rθ)rcosθ+(rsinθ+rcosθ)r
Substitute r = 4 and θ = π/2
δw/δθ = (4sinπ/2+4π/2)-4sinπ/2+(4cosπ/2+4π/2)4cosπ/2+(4sinπ/2+4cosπ/2)(4)
Note that cos π/2 = 0 and sinπ/2 = 1
δw/δθ = (4+2π)(-4)+(0+2π)(0)+(4(1)+4(0))(4)
δw/δθ = -16-8π+0+4(4)
δw/δθ = -16+16-8π
δw/δθ = -8π
Find the slope for the line that passes thru the points (-2, 7) and (4, 18)
Answer:
[tex]m=\frac{11}{6}[/tex]
General Formulas and Concepts:
Pre-Alg
Order of Operations: BPEMDASAlg I
Slope Formula: [tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]Step-by-step explanation:
Step 1: Define
Point (-2, 7)
Point (4, 18)
Step 2: Solve for slope m
Substitute: [tex]m=\frac{18-7}{4+2}[/tex]Subtract/Add: [tex]m=\frac{11}{6}[/tex]Answer:
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In order to accumulate enough money for a down payment on a house, a couple deposits $589 per
month into an account paying 3% compounded monthly. If payments are made at the end of each period,
how much money will be in the account in 4 years?
Type the amount in the account: $
(Round to the nearest dollar.)
you have four years 1767 dollars in account
Mr. Dudley is writing a test for his mathematics class. The test will have true/false
questions worth 2 points each and multiple-choice questions worth 4 points each for a
total of 100 points. He wants to have twice as many multiple-choice questions as
true/false questions. How many true/false questions and multiple-choice questions will
be on the test?
Answer:
10
Step-by-step explanation:
so x=true/false questions
y=multiple-choice questions
2x+4y=100
2x=y
plug in 2x for y in the first equation
2x+4(2x)=100
10x=100
x=10
y=20
The total questions would include 10 true/false questions and 20 multiple-choice questions.
We have Mr. Dudley who is writing a test for his mathematics class. The test will have true/false questions worth 2 points each and multiple-choice questions worth 4 points each for a total of 100 points. He wants to have twice as many multiple-choice questions as true/false questions.
We have to determine how many true/false questions and multiple-choice questions will be on the test.
What do understand by Modelling of a Equation ?The modelling of equation is done to derive a mathematical relation among the terms defined in a mathematical statement.
According to the question -
Assume that the number of true/false questions be x.
Assume that the number of multiple-choice questions be y.
Then -
y = 2x
Points for each true/false questions - 2 points
Points for each multiple-choice questions - 4 points
Total points of test = 100 points
Now,
Model the equation on the basis of above information -
2x + 4y = 100
2x + 4 (2x) = 100
2x + 8x = 100
10x = 100
x = 10
Therefore -
y = 2x = 2 x 10 = 20
Hence, the total questions would include 10 true/false questions and 20 multiple-choice questions.
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The radius of a circle is 10 meters. What is the angle measure of an arc bounding a sector
with area 150 square meters?
whats 4/5 of 3/4 and whats 2/3 of 1/4
Answer:
4/5 of 3/4 = 3/5
2/3 of 1/4 = 1/6
Step-by-step explanation:
A Norman window is a rectangle with a semicircle on top. Suppose that the perimeter of a particular Norman window is to be 25 feet. What should the rectangle's dimensions be in order to maximize the area of the window and, therefore, allow in as much light as possible? (Round your answers to two decimal places.)width ________ ftheight _______ ft
Answer:
[tex]Length =\frac{25}{4 + \pi}[/tex] and [tex]Width = \frac{50}{4+\pi}[/tex]
Step-by-step explanation:
This question is better understood with an attachment.
See attachment for illustration.
Given
Represent Perimeter with P
[tex]P = 25ft[/tex]
Required
Determine the dimension of the rectangle that maximizes the area
First, we calculate the perimeter of the rectangular part of the window.
From the attachment, the rectangle is not closed at the top.
So, The perimeter would be the sum of the three closed sides
Where
[tex]Width = 2x[/tex]
[tex]Length = y[/tex]
So:
[tex]P_{Rectangle} = y + y + 2x[/tex]
[tex]P_{Rectangle} = 2y + 2x[/tex]
Next, we determine the circumference of the semi circle.
Circumference of a semicircle is calculated as:
[tex]C = \frac{1}{2}\pi r[/tex]
From the attachment,
[tex]Radius (r) = x[/tex]
So, we have:
[tex]C = \frac{1}{2}2\pi * x[/tex]
[tex]C = \pi x[/tex]
So, the perimeter of the window is:
[tex]P = P_{Rectangle} + C[/tex]
[tex]P =2y + 2x + \pi x[/tex]
Recall that: [tex]P = 25[/tex]
So, we have:
[tex]25 =2y + 2x +\pi x[/tex]
Make 2y the subject
[tex]2y = 25 - 2x - \pi x[/tex]
Make y the subject:
[tex]y = \frac{25}{2} - \frac{2x}{2} - \frac{\pi x}{2}[/tex]
[tex]y = \frac{25}{2} - x - \frac{\pi x}{2}[/tex]
Next, we determine the area (A) of the window
A = Area of Rectangle + Area of Semicircle
[tex]A = 2x * y + \frac{1}{2}\pi r^2[/tex]
[tex]A = 2xy + \frac{1}{2}\pi r^2[/tex]
Recall that
[tex]Radius (r) = x[/tex]
[tex]A = 2xy + \frac{1}{2}\pi x^2[/tex]
Substitute [tex]\frac{25}{2} - x - \frac{\pi x}{2}[/tex] for y in [tex]A = 2xy + \frac{1}{2}\pi x^2[/tex]
[tex]A = 2x(\frac{25}{2} - x - \frac{\pi x}{2}) + \frac{1}{2}\pi x^2[/tex]
Open Bracket
[tex]A = 2x * \frac{25}{2} - 2x * x - 2x * \frac{\pi x}{2} + \frac{1}{2}\pi x^2[/tex]
[tex]A = 25x - 2x^2 - \pi x^2 + \frac{1}{2}\pi x^2[/tex]
[tex]A = 25x - 2x^2 - \frac{1}{2}\pi x^2[/tex]
To maximize area, we have to determine differentiate both sides and set A' = 0
Differentiate
[tex]A' = 25 - 4x - \pi x[/tex]
[tex]A' = 0[/tex]
So, we have:
[tex]0 = 25 - 4x - \pi x[/tex]
Factorize:
[tex]0 = 25 -x(4 + \pi)[/tex]
[tex]-25 =-x(4 + \pi)[/tex]
Solve for x
[tex]x = \frac{-25}{-(4+\pi)}[/tex]
[tex]x = \frac{25}{4+\pi}[/tex]
Recall that
[tex]Width = 2x[/tex]
[tex]Width = 2(\frac{25}{4+\pi})[/tex]
[tex]Width = \frac{50}{4+\pi}[/tex]
Recall that:
[tex]y = \frac{25}{2} - x - \frac{\pi x}{2}[/tex]
Substitute [tex]\frac{25}{4+\pi}[/tex] for x
[tex]y = \frac{25}{2} - (\frac{25}{4+\pi}) - \frac{\pi (\frac{25}{4+\pi})}{2}[/tex]
[tex]y = \frac{25}{2} - (\frac{25}{4+\pi}) - \frac{\frac{25\pi}{4+\pi}}{2}[/tex]
[tex]y = \frac{25}{2} - (\frac{25}{4+\pi}) - \frac{25\pi}{4+\pi} * \frac{1}{2}[/tex]
[tex]y = \frac{25}{2} - \frac{25}{4+\pi} - \frac{25\pi}{2(4+\pi)}[/tex]
[tex]y = \frac{25(4+\pi) - 25 * 2 - 25\pi}{2(4 + \pi)}[/tex]
[tex]y = \frac{100+25\pi - 50 - 25\pi}{2(4 + \pi)}[/tex]
[tex]y = \frac{100- 50+25\pi - 25\pi}{2(4 + \pi)}[/tex]
[tex]y = \frac{50}{2(4 + \pi)}[/tex]
[tex]y = \frac{25}{4 + \pi}[/tex]
Recall that:
[tex]Length = y[/tex]
So:
[tex]Length =\frac{25}{4 + \pi}[/tex]
Hence, the dimension of the rectangle is:
[tex]Length =\frac{25}{4 + \pi}[/tex] and [tex]Width = \frac{50}{4+\pi}[/tex]
[[[click on the image to make bigger]]]
I really need questions 2 and 4 for this!! please
Answer:
It equals pizza 3’5.42 inch
Step-by-step explanation:
How many solutions does this system have?
-x + 2y = 16
4x - 8y = -64
What type of number is 739?.
A. Neither
B. Prime
C. Composite
ANSWER
For 739, the answer is: prime anslo written as B
Step-by-step explanation:
739 is a prime number because it has only two distinct divisors: 1 and itself (739).
HAVE A GOOD DAY!
Answer:
its neither
Step-by-step explanation:
Which number line shows the solution to the inequality 5x + 3> - 17
Answer:
C would be the correct number line
Step-by-step explanation:
5x ≥ - 17 - 3
5x ≥ -20
5x/5 ≥ -20/5
x ≥ 4
Missy wants to find the surface area of a snack box in her pantry her work is shown below
Answer:
Step 2: Missy did not multiply the area of each face by 2 before adding.
Step-by-step explanation:
I took the test :)
plz tell me 12 x 12 = and 12 x 13 =
Answer:
12 x 12 = 144, 12 x 13 = 156
Step-by-step explanation:
The sum of two numbers is 12.
When three times the first number is added to 5 times the second number, the result is 44.
Find the two numbers.
A 9 and 3
B) 8 and 4
C) 10 and 2
D) 7 and 5
Answer:
b
Step-by-step explanation:
8*3
=24
4*5
=20
20+24
=44
24 = 3(n–5)
What is the answer
Step-by-step explanation:
24=3n-15 or,25+15=3n or,39=3n or,39/3=n or,n=13 therefore the value of n is 13. I think this answer is helpful for you
Answer: n = 13
Step-by-step explanation:
24=3(n-5) - First distribute the 3 to the n and the 5. Which you would than get 3n and -15
24=3n-15 - Now add the 15 to both sides which would cause it to cancel out on the left side of the equal side.
39=3n - Now divide the 3 from 3n on both sides of the equal side.
n=13 - Once you do that you will get n = 13. That is your answer!
Ben and josh went to the roof of their 40-foot tall high school
use an identity to solve the equation on the interval [0,2pi) sin x cos x = -1/4 x=
Answer:
The solution of the given equation is x = 105 °∈ ( 0 , 2pi)Step-by-step explanation:
Step(i):-
Given equation is sin x cos x = -1/4
[tex]2(2sinxcosx) = -1[/tex]
we know that trigonometry formula
2 sin x cos x = sin 2x
2 ( sin 2 x) = -1
sin2x = -1/2
Step(ii):-
sin2x = [tex]\frac{-1}{2} = sin (\pi +\frac{\pi}{6}[/tex]
sin2x = sin 210 2x = 7π/6 2x = 210° x = 105 °The solution of the given equation is x = 105 °∈ ( 0 , 2pi)simplify 6³÷2³×9^-2
Do I have this correct or did I read the instructions wrong? This is due tomorrow and I’m still on slide 1. Pls help!
Answer:
Hey man! Just saw this and that answer is not correct! I see how you were thinking tho. Here is how it should be graphed.
Step-by-step explanation:
I have marked the correct dots in green.
Which of the expressions below is greater than 15? Select all that apply.
A) 4.583 + 10.673
B) 26.712 – 11.348
C) 45.768 – 28.945
D) 7.312 + 7.145
E) 11.32 + 3.11
Answer:
A
B
C
Step-by-step explanation:
Manuel earned a grade of 80%. He got 16 correct. How many problems were on the test? plz solve quick
Answer:
20
Step-by-step explanation
If the ratio of the sides of two similar prisms is 4:1. Is the ratio of the volume of the prisms the same? (4:1)
Answer:
The ratio of their volumes is not the same 4:1, but [tex](4:1)^3[/tex] = 64:1.
Step-by-step explanation:
Measurements in Similar Figures
In similar figures, if the ratio of any of these corresponding lengths is expressed as a:b then the ratio of the other corresponding lengths can also be expressed as a:b.
In similar figures, if the ratio of any of these corresponding lengths is expressed as a:b then the ratio of the areas can be expressed as (a:b)^2 and the ratio of the volumes can be expressed as (a:b)^3.
We are given the ratio of the sides of two similar prisms as 4:1. The ratio of their volumes is not the same 4:1, but [tex]\mathbf{(4:1)^3}[/tex] = 64:1.
Is the network in d) an Euler circuit? Can this network can be traversed?
...
А
B
А
B
b)
G
X
F
H
H
E
D
D
А
E B
А
B
d)
G
E
F
DF
C
D
C
Answer:
If a graph is an Euler Circuit that mean that it can be traversed and begins and has all even verticies. This allows you to start and stop at the same verticie.
Step-by-step explanation:
If the circumference of the circle is 24 inches what is the
approximate diameter
Answer:
7.64 in.
Step-by-step explanation:
The diameter of the circle whose circumference is 24 inches is 7.654 inches.
What is a circle?A circle is a two-dimensional object made up of points that are spaced out from a given point (center) on the plane by a fixed or constant distance (radius).
Given:
The circumference of the circle, C = 24 inches,
Calculate the radius of the circle as shown below,
Circumference = [tex]2\pi r[/tex]
C = 2 × π r
r = 24 / 2π
r = 3.819
r = 3.82 inches
Calculate the diameter as shown below,
Diameter = 2 × r
Diameter = 2 × 3.82
Diameter = 7.639 inches
Thus, the diameter is 7.64 inches.
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You wish to have $500 in a year. If you have a savings account that pays 6% simple interest, how much do you need to put into the account?
Answer:
$8333.3
Step-by-step explanation:
The problem here is to find the principal that will yield an interest of $500 in a year at a rate of 6%.
Interest = [tex]\frac{PRT}{100}[/tex]
P is the principal
R is the rate
T is the time
The time is 1 year;
500 = [tex]\frac{P x 6 x 1}{100}[/tex]
6P = 50000
P = [tex]\frac{50000}{6}[/tex] = $8333.3
Evaluate the expression 54⁰
Answer:
1
Step-by-step explanation:
All numbers to the power of 0 are 1.
PLS GIVE BRAINLIEST
I WILL GIVE BRAINLIEST
Rewrite 12x + 3y = 6 in slope-intercept form. Give the slope and y-intercept.
y =
m =
b =
Answer:
12x + 3y = 6 in slope-intercept form.y = -4x+2m = -4b =(0,2)what is 3/4 and 5/12 simplified in fraction form plz idk
Answer:
Well 3/4 & 5/12 are already simplified and in fraction form, if youre
looking for decimal form its gonna be .75 &.41
Step-by-step explanation:
A fair coin is flipped 10 times and the sequence of heads and tails is noted. In how many outcomes are there in at least 3 tails?a. 904 b. 120 c. 176 d. 24 e. 32
Answer:
P(X ≥ 3) = 0.94538
Step-by-step explanation:
When flipping a coin, probability of getting a tail is p= 0.5.
Number of times flipped; n = 10
Now, this is a binomial probability distribution problem with the formula;
P(X = x) = C(n, r) × p^(x) × (1 - p)^(n - x)
Probability of getting at least 3 tails is;
P(X ≥ 3) = P(3) + P(4) + P(5) + P(6) + P(7) + P(8) + P(9) + P(10)
P(3) = C(10, 3) × 0.5³ × (1 - 0.5)^(10 - 3)
P(3) = 0.1172
P(4) = C(10, 4) × 0.5⁴ × (1 - 0.5)^(10 - 4)
P(4) = 0.2051
From online binomial probability calculator, we have the remaining as;
P(5) = 0.2461
P(6) = 0.2051
P(7) = 0.1172
P(8) = 0.0439
P(9) = 0.0098
P(10) = 0.00098
Thus;
P(X ≥ 3) = 0.1172 + 0.2051 + 0.2461 + 0.2051 + 0.1172 + 0.0439 + 0.0098 + 0.00098
P(X ≥ 3) = 0.94538
A university has raised $6,000 for a new scholarship fund. A university trustee offers to match the donation up to 30% if the university can raise $5,000 more for the fund. If the university is able to raise the extra amount, how much money will be in the fund after the trustee's donation?
Answer:
$14300
Step-by-step explanation:
30% is the same as .3
They are raising 5k more to the 6k so 5000+6000= 11000
.3*11000= 3300...so the trustee is adding 3300 to the fund, making the total fund 3300+11000= $14300
help plz and it’s not 61.6 because that’s what someone has said
Answer: 250 total kids and 140 girls
Step-by-step explanation:
%56=girls that means %44= boys that means 110 is %44 of the number of kids is 110/44*100= 2.5*100=250kids 56%=girls that means %56 of 250 which is 140 girls