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
Answers
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]
Related Questions
What does 0.05 x 300 represent?
Answers
Answer:
15
Step-by-step explanation:
Complete the area model. Find the product of 2.3 x 1.5
Answers
The product of 2.3 × 1.5 from the area model is 3.45
The product of two numbers implies the multiplication of the two numbers. Here, the two numbers to be multiplied together are decimal numbers.
Using the long multiplication method.
2.3
× 1.5
1 1 5
+ 2 3
3 . 4 5
So, what we did basically is to first multiply the two numbers normally and then, decide how many decimal places are the two numbers which two.
Therefore, the product of 2.3 × 1.5 from the area model is 3.45
Learn more about product of a number here:
https://brainly.com/question/21264607?referrer=searchResults
which is irrational?
A. 5/2
B. 5.22
C. 2/5
D. √5/2
Answers
Answer:
D
Step-by-step explanation:
Plz mark as brainliest!!!
PLEASEEEE HELPPP MEEE :(
Answers
Answer:
Question 5 is B
Because after I simplified I got B and its the only one that makes sense.
For its beef stew, Betty Moore Company uses aluminum containers that have the form of right circular cylinders. Find the radius and height of a container if it has a capacity of 44 in.3 and is constructed using the least amount of metal. (Round your answers to two decimal places.)
Answers
Answer:
[tex]1.91\ \text{in}[/tex]
[tex]3.84\ \text{in}[/tex]
Step-by-step explanation:
V = Volume of cylinder = [tex]44\ \text{in}^3[/tex]
h = Height of cylinder
r = Radius of cylinder
Volume of cylinder is given by
[tex]V=\pi r^2h\\\Rightarrow h=\dfrac{V}{\pi r^2}\\\Rightarrow h=\dfrac{44}{\pi r^2}[/tex]
Total surface area of a cylinder is given by
[tex]S=2\pi r^2+2\pi rh\\\Rightarrow S=2\pi r^2+2\pi r\times\dfrac{44}{\pi r^2}\\\Rightarrow S=2\pi r^2+\dfrac{88}{r}[/tex]
Differentiating with respect to radius
[tex]\dfrac{dS}{dr}=4\pi r-\dfrac{88}{r^2}[/tex]
Equating with zero
[tex]4\pi r-\dfrac{88}{r^2}=0\\\Rightarrow 4\pi r=\dfrac{88}{r^2}\\\Rightarrow r^3=\dfrac{88}{4\pi}\\\Rightarrow r=(\dfrac{22}{\pi})^{\dfrac{1}{3}}\\\Rightarrow r=1.91\ \text{in}[/tex]
Double derivative of S
[tex]\dfrac{d^2S}{dr^2}=4\pi+176>0[/tex]
So [tex]r[/tex] is minimum at [tex]\dfrac{dS}{dr}=0[/tex]
[tex]h=\dfrac{44}{\pi r^2}=\dfrac{44}{\pi 1.91^2}\\\Rightarrow h=3.84\ \text{in}[/tex]
So the radius and height of the cylinder is [tex]1.91\ \text{in}[/tex] and [tex]3.84\ \text{in}[/tex] respectively such that the least amount of metal is used.
If f(x) = 4x-3, which of the following is the inverse of f(x)?
7x+3
O A. F'(X) =
4
4x-3
O B. F'(x) = 447
7x-3
O c. F'(x) =
4
O D. F'(x) = 4***
SUBMIT
Math
Answers
Answer:
[tex]\huge\boxed{f^{-1}(x)=\dfrac{x+3}{4}=\dfrac{1}{4}x+\dfrac{3}{4}}[/tex]
Step-by-step explanation:
[tex]f(x)=4x-3\to y=4x-3\\\\\text{exchange}\ x\ \text{to}\ y\ \text{and vice versa}\\\\x=4y-3\\\\\text{solve for}\ y\\\\4y-3=x\qquad|\text{add 3 to both sides}\\\\4y-3+3=x+3\\\\4y=x+3\qquad|\text{divide both sides by 4}\\\\\dfrac{4y}{4}=\dfrac{x+3}{4}\\\\y=\dfrac{x+3}{4}\to y=\dfrac{1}{4}x+\dfrac{3}{4}[/tex]
Solve 3x2 + 4x = 2. (2 points)
Answers
Answer:
The answer is (-2±√10)/3
Step-by-step explanation:
so if it is 3x^2+4x=2 then
set one side to zero
subtract 2 from both sides
3x^2+4x-2=0
this is not factorable by normal means so use quadratic formula which is if you have the equation in ax^2+bx+c=0 form you can solve for x if you put it into this equation quadratic formula so if you were to input it into this equation you would get
a=3
b=4
c=-2
the solution is: (-2±√10)/3
You are given the explicit formula below. Identify if will produce an arithmetic or geometric sequence. Also identify the common difference or common ratio
f(n) = 25(4)^n-1
1. Geometric, common ratio of 1/4
2. Geometric, common ratio of 4
3. Arithmetic, common ratio of 25
4. Arithmetic, common ratio of 4
Answers
Answer:
2. Geometric, common ratio of 4Step-by-step explanation:
Given is the exponential function which is a geometric sequence
It has common ratio of 4
Correct answer option:
2. Geometric, common ratio of 4The difference between the sample value and the true value in the population under study is referred to as _______.
Answers
Answer:
a. sampling error
Step-by-step explanation:
These are options for the question below;
a. sampling error
b. random error
c. measurement error
d. chance correlation
e. none of these
Sampling error can be regarded as statistical error, this do occur when the person analysing the data just select portion out of the data, which doesn't fully cover for the whole population of the data, and after the analysis the gotten result doesn't resemble the kind of result that could have gotten if the whole population of Data is used. It occurs where there is more difference exist between population parameter and a sample statistic.
Mathematically sampling error can be calculated using below formula
Sampling error= Z √[p(1-p)/n] [1-√(N/n)
Where
N= population size
n=sample size
Z= score for the selected confidence level
P= proportion of people surveyed
It should be noted that The difference between the sample value and the true value in the population under study is referred to as sampling error
-9 is an example of what
Answers
Answer:
A negative number, a negative integer, a negative multiple of 3, etc.
Step-by-step explanation:
Answer:
integer
???????
Step-by-step explanation:
I'm not sure
Yesterday, the temperature in a city dropped from 9°C to –9°C, as shown below.
The expression 9 + (–18) represents the final temperature. Which of the following is an equivalent way to describe this temperature?
|–18| degrees in a negative direction from 9 degrees
|–18| degrees in a positive direction from 9 degrees
|–9| degrees in a negative direction from 9 degrees
|–9| degrees in a positive direction from 9 degrees
Answers
Answer:
b
Step-by-step explanation:
absoulute value is never negative.
please help
compare. Write <, >, or =.
Answers
Answer:
1. <
2. >
3. >
4. =
5. <
6. <
7. >
8. >
9. >
10. <
11. >
12. <
13. <
14. =
15. =
16. =
Step-by-step explanation:
A plane travels 264 miles in 1.1 hours against the wind. On the return trip, it travels the same 264 miles in 1
hour. Find the speed of the wind.
Answers
Answer:
The speed of the wind is 12 miles per hour.
Step-by-step explanation:
Given that the plane travels 264 miles in 1.1 hours with a headwind, the following calculation must be performed to determine its speed:
264 / 1.1 = X
240 = X
Thus, the speed of the plane into the headwind was 240 miles per hour. Now, on the return, with the wind in favor, the route is completed in exactly 1 hour.
Therefore the wind exerts a difference of 24 miles per hour between one trip and another, with which, if it remains stable, its speed is 12 miles per hour (24 / 2).
A random sample is made of 256 middle managers concerning their annual incomes. The sample mean is computed to be $35,420. If the population standard deviation is $2,050. What is the standard error of the mean?
a. $128.125
b. $138.36
c. $2.050
d. $8.01
Answers
Answer: a. $128.125
Step-by-step explanation:
The standard error of the mean is given by :
[tex]SE=\dfrac{\sigma}{\sqrt{n}}[/tex] , where [tex]\sigma[/tex] = population standard deviation , n= sample size.
Given: [tex]\sigma=\$2,050[/tex]
n= 256
Then, the standard error of the mean:-
[tex]SE=\dfrac{2050}{\sqrt{256}}\\\\=\dfrac{2050}{16}=\$128.125[/tex]
Hence, option a. is correct.
The CEO of a large company claims that 85% of customers are repeat customers. They define a repeat customer as someone who makes more than one purchase per month. A random sample of 200 customers shows that 162 are repeat customers. Do these data provide convincing evidence at the 5% significance level that less than 85% of customers of this company are repeat customers?
Answers
Answer:
1. customers
2. all customers
3. 170
4. 30
5. 10
Step-by-step explanation:
edgen 2020 :)
275964.618882 the nearest hundreth
Answers
275964.62 is to the nearest hundredth
Step-by-step explanation:
3. Which number is a distance of 4 units away from 2 and a distance of 2 units from -4?
HH
-6
-5
-4
-3
-2
-1
0
1
2.
3
4
5
6
Answers
Answer:
-2
Step-by-step explanation:
Gabriela drank three fourths of her glass of milk and jenny drank six eighths of her glass of milk if the glasses were the same size did they drink the same amount ? Use cross multiplication to prove your answer
Answers
Answer:
just croos multi
Step-by-step explanation:
its very easy
I WILL GIVE YOU 20 POINTS AND THE BRAINLYEST
all of the points in the picture are on the same line.
Find the slope on the like exain or show your reasoning
write and equation for the line.
find the values for A and B. Explain your reasoning.
Answers
Answer/Step-by-step explanation:
✍️Slope of the line using two points, (2, 2) and (6, 10),
[tex] slope (m) = \frac{y_2 - y_1}{x_2 - x_1} = \frac{10 - 2}{6 - 2} = \frac{8}{4} = 2 [/tex]
✍️To find the equation of the line in slope-intercept form, we need to find the y-intercept (b).
Substitute x = 2, y = 2, and m = 2 in y = mx + b, and solve for b.
2 = (2)(2) + b
2 = 4 + b
2 - 4 = b
-2 = b
b = -2
Substitute m = 2 and b = -2 in y = mx + b.
✅The equation would be:
[tex] y = 2x + (-2) [/tex]
[tex] y = 2x - 2 [/tex]
✍️To find the value of a, plug in (a, 8) as (x, y) into the equation of the line.
[tex] 8 = 2(a) - 2 [/tex]
[tex] 8 = 2a - 2 [/tex]
Add 2 to both sides
[tex] 8 + 2 = 2a [/tex]
[tex] 10 = 2a [/tex]
Divide both sides by 2
[tex] \frac{10}{2} = a [/tex]
[tex] 5 = a [/tex]
a = 5
✍️To find the value of b, plug in (4, b) as (x, y) into the equation of the line.
[tex] b = 2(4) - 2 [/tex]
[tex] b = 8 - 2 [/tex]
[tex] b = 6 [/tex]
Name 3 the rays in the figure
Answers
Answer:
Where is the figure?
Step-by-step explanation:
A ray looks like this though:
Help plz math algebra honors?!
Answers
Answer:
y=1
To check your answer:
20(1)-7=13
20-7=13
13=13
PLZ HURRY IT'S URGENT!!!
Petrucio has $50 to spend on entertainment. Music downloads are $2.00 each and movie downloads are $5.00 each. What possible combinations can Petrucio buy? SELECT ALL THAT APPLY
options:
8 songs and 6 movies
20 songs and 2 movies
4 songs and 10 movies
7 songs and 8 movies
Answers
Answer:
*20 Songs and 2 Movies
*8 Songs and 6 movies
Step-by-step explanation:
When do you draw a hole in a piecewise function?
Answers
Answer:
you just draw a circle indicating that it is a hole. Your welcome
The new Xbox series gaming console sells for 499 all units are sold out at stores but can be found online for 34% more than the original price how much would it cost to get it online at the marked up price
Answers
Which of the following values are solutions to the inequality 9 < -10 – 4x?
Answers
Answer:
ndndndndndn
Step-by-step explanation:
svhddbxbdnnddjdnfn
help please- asap :}
Answers
Answer:
The digits in bold are those that were given, and other two we had to fill. The table below contains the answer.
Step-by-step explanation:
We need to complete the table.
Positive Integer: value having + sign
Negative Integer : Value having - sign
The digits in bold are those that were given, and other two we had to fill
Positive Integer Negative Integer Value
15 -15 15
101 -101 101
4 -4 4
82 -82 82
1121 -1121 1121
33 -33 33
10 -10 10
999 -999 999
47 -47 47
1 -1 1
Homer is 30 feet below sea level and Marge is 45 feet above sea level. Bart’s elevation is at the exact midpoint of those two values. What is the expression that model this problem, and which is Bart’s elevation?
Answers
Answer:
14.5 feet
Step-by-step explanation:
the midpoint is halfway from 30 to 45 so be(bart elevation) b.e = 45 - 30 / 2
7.5 m above sea level
__________________________________________________________
Step-by-step explanation:We are given:
The elevation of Homer = -30 feet [30 feet below sea level]
The elevation of Marge = +45 feet [45 feet above sea level]
The elevation of Bart is at the exact mid-point of the elevations of Homer and Marge
The elevation of Bart:
We are given that the elevation of Bart is at the exact mid-point of the elevations of Homer and Marge
So, Half the distance between the elevation of Homer and Marge is the elevation of Bart
Elevation of Bart (with respect to the elevation of Homer) =
(elevation of Marge - Elevation of Homer) / 2
replacing the variables with the suitable values:
(+45 - (-30))/2
(45 + 30) / 2
75 / 2
Elevation of Bart (w.r.t. Homer) = 37.5 feet
Since this is the elevation of Bart with respect to Homer, we can say that Bart is 37.5 m above Homer
So, we can say that:
Elevation of Bart (w.r.t Homer) = Elevation of Bart - Elevation of Homer
replacing the values
37.5 = Elevation of Bart -(-30)
37.5 = Elevation of Bart + 30
Elevation of Bart = 7.5 m above sea level [subtracting 30 from both sides]
A student finds a positive correlation between the number of beds in a home and the number of plates in the kitchen.
Which variable is most likely the lurking variable that explains the correlation?
A: height of tallest person in the home
B: age of oldest person in the home
C: number of children in the home
D: number of pets in the home
im not doing great in math and i really need some help with this
Answers
Answer:
here you go this is for confirmation
Step-by-step explanation:
Write an equation for 51 divided by 3 is k
Answers
Answer:
51/3 = 17
Step-by-step explanation:
3 can go into 5 one time (1)
5 minus 3 equals 2.
Bring down the one, make sure the 2 and 1 are beside. (21)
How many times can 3 go in to 21 ?
7 !
So, put 1 and 7 together, and get 17!
How to change a fraction to a decimal
Answers
Answer:
just divide the numerator by the denominator
Step-by-step explanation:
an example is ⅔ as a decimal is about .666 or .7