The pool dimensions that will minimize the cost of construction are length of square bottom = 20 ft and height of pool = 5 ft
Let l be the length of side of the square bottom of the pool and h be the height of the pool.
Its volume V = l²h
Now, the total surface area of the pool equal the area of its sides plus the area of its base.
The area of its 4 sides is 4lh.
Since the cost of the side of the pool is $80 per square foot, the total cost for the sides of the pool is C = $80 × 4lh = $ 320lh
Also, The area of its square bottom is l².
Since the cost of the side of the pool is $40 per square foot, the total cost for the square bottom of the pool is C' = $40 × l² = $ 40l²
So, the total cost of the pool is C" = C + C' = 320lh + 40l²
C" = 320lh + 40l²
Since the volume equals 2000 ft³, V = l²h
2000 = l²h
h = 2000/l²
Substituting h into C", we have
C" = 320lh + 40l²
C" = 320l × 2000/l² + 40l²
C" = 640000/l + 40l²
To find the value of l which makes C" minimum, we differentiate C" with respect to l and equate it to zero.
So, dC"/dl = d(640000/l + 40l²)/dl
dC"/dl = d(640000/l)/dl + d(40l²)/dl
dC"/dl = -640000/l² + 80l
Equating dC"/dl to zero, we have
-640000/l² + 80l = 0
-640000/l² = -80l
Cross-multiplying, we have
640000 = 80l³
Dividing through by 80, we have
l³ = 640000/80
l³ = 8000
Taking cube root of both sides, we have
l = ∛8000
l = 20 ft
We differentiate C" twice to determine if this value of l gives a minimum for C".
So, d²C"/dl² = d(-640000/l² + 80l)/dl
d²C"/dl² = d(-640000/l²)/dl + d(80l)/dl
d²C"/dl² = 640000/l³ + 80
Substituting l = 20, we have
d²C"/dl² = 640000/l³ + 80
d²C"/dl² = 640000/20³ + 80
d²C"/dl² = 640000/8000 + 80
d²C"/dl² = 80 + 80
d²C"/dl² = 160 > 0
Since d²C"/dl² = 160 > 0. So, l = 20 ft gives a minimum for C".
Since h = 2000/l²
Substituting l = 20 into the equation, we have
h = 2000/l²
h = 2000/20²
h = 2000/400
h = 5 ft
So, the pool dimensions that will minimize the cost of construction are length of square bottom = 20 ft and height of pool = 5 ft
Learn more about dimensions of a pool here:
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simplify the following 6b-8(46 - 9) + 3b
The value of 6b-8(46 - 9) + 3b is 9b - 296.
The equation given is 6b-8(46 - 9) + 3b, the calculation will go thus:
= 6b-8 (46 - 9) + 3b
= 6b-8 (46 - 9) + 3b
= 6b - 8(37) + 3b
= 6b - 296 + 3b
= 6b + 3b - 296
= 9b - 296
Answer: 9b-296
Step-by-step explanation:
Subtract the numbers 6−8 (46−9)+3 6−8(37)+3 2
Multiply the numbers 6−8⋅37+3 6−296+3
Combine like terms 6b−296+3b
Ur answer
9b−296
tell the answer of the last q i asked pls
q was :-(
Rohan spent 20% of his pocket money on transport and ₹60 on his breakfast.If he spent 15% of the remaining money on his lunch and had ₹340 left, what was his pocket money?
He spent on transport = 20%
spent on breakfast = 60/-
spent on lunch = 15%
remaining amount = 340
rs he spent on transport = 20/100 × 340 =68
rs he spent on lunch = 15/100 × 340 = 51
Therefore, total of his pocket money = 68 + 51 + 60 + 340
= ₹519
Plug in missing values to make it a function…. Please help
Answer:
p = 5
Step-by-step explanation:
Judging from (0,0) and (10,-20) as given in the chart, the function is y = -2x.
Substituting that for the second row, you would get the equation -10 = -2x.
Simplifying, you get x = 5, so the value of p is 5.
Answer:
5
Step-by-step explanation:
First find the slope
m = ( y2-y1)/(x2-x1)
m = (-20-0)/(10-0)
= -20/10
= -2
We know the slope and have two points, (0,0) and (p,-10)
-2 = ( -10-0)/(p-0)
-2 = -10/p
Multiply each side by p
-2p = -10
Divide each side by -2
p = -10/-2
p = 5
What is the CONJUGATE of the expression -3 - 4i ?
What is the absolute value of -3 - 4i?
with calculations
[tex]\text{Conjugate of -3-4i is -3+4i}\\\\|-3-4i| = \sqrt{(-3)^2 + (-4)^2} = \sqrt{9+16} = \sqrt{25} =5[/tex]
10 students volunteer to help fold paper stars for a charity project. If an additional 5 students help out, they will be able to finish the job 3 days earlier. The number of days required to finish the job is inversely proportional to the number of students who help out. Find the additional number of students needed to help out in order to finish the job 4 days earlier.
Answer:
Above is the step-by-step solution.
what is the sum of 5.4 + (-9.7)
Answer:
-4.3
Step-by-step explanation:
What is the slope of the line that passes through the points (-3,3) and (-3, 13)?
Write your answer in simplest form.
Answer:
ΔY = 10
Step-by-step explanation:
HELP!!! Worth 50 points
Answer:
with what
Step-by-step explanation:
I am confused there is no question at all showing
Answer:
Answer:
The correct answer is C - 7.8 < 7 5/6 < 7.9
Step-by-step explanation:
First, convert 7 5/6 to decimal form --> 7.83.
If you don't know how to convert, think about what 5/6 is equal to and put it in decimal form. Add your decimal to the whole number, and there is your answer.
7.83 is in between 7.8 and 7.9, so it must be the answer.
I hope this helps!
Step-by-step explanation:
Write a recursive formula and an explicit formula for the following arithmetic sequence.
4.25, 4.75, 5.25, 5.75, ...
(12a-9b+7)+(2a-3b-14)
Answer:
14a - 12b - 7
Step-by-step explanation:
What is the value of this expression?
−29−(−13÷35)
Answer:
-29 13/35
Step-by-step explanation:
Answer number eleven and thirteen please
Answer:
Both are right trianglesStep-by-step explanation:
Use Pythagorean to decide
#11Sides 12, 16, 20
12² + 16² = 20²400 = 400Right triangle#13Sides 2.4, 4.5, 5.1
2.4² + 4.5² = 5.1²26.01 = 26.01Right triangle30 POINTS, I NEED FAST AND CORRECT ANSWERS PLEASE!!!!
The average cost of a compact car at a certain dealership over the last 5 years has ranged from $14,000
to $16,000. Suppose you were going to plot these points on a coordinate grid.
(a) What is a good scale to use for the y-axis? Explain your reasoning.
(b) What is a good interval to use for the y-axis? Explain your reasoning.
Answer:
Plz give brainliest
Step-by-step explanation:
I believe
A) 0 - 20,000
B) Interval= 2000 or 3000
Turn into a equivalent form 6x²+13x+5
Answer:
Assuming the questions wants another form of 6x²+13x+5:
(2x+1)(3x+5) would work.
Step-by-step explanation:
Multiply (2x+1)(3x+5) and you'll get 6x^2+13x+5
how is the answer 4??
Answer:
see below
Step-by-step explanation:
log sqrt5 (25) = y
we know that loga (b) = c can be rewritten as a^c = b
sqrt(5) ^ y = 25
Rewriting sqrt(5) as 5^1/2 and 25 as 5^2
5^1/2 ^ y = 5^2
we know a^b^c = a^ (b*c)
5 ^ 1/2y = 5^2
1/2y = 2
y = 4
someome help in math please
Answer:
[tex] - n + 4(2c + 2) + 6n = .... \\ - 5 + 4(4 + 2) + 30 = .... \\ 19 + 30 = 49[/tex]
your answer is 49PLS HELP AMSWER ANYONE PLS ILL GIVE BRAINLKEST THANKS
Answer:
5. w ≠ 8
Step-by-step explanation:
#1 is the expression for "The amount of water is greater than eight ounces." This technically means it differs from eight ounces, but it's too specific for what the question is asking.
#2 is the expression for "The amount of water is greater than or equal to eight ounces." It doesn't necessarily differ from eight ounces.
#3 is the expression for "The amount of water is less than eight ounces." Same issue as #1.
#4 is the expression for "The amount of water is greater than eight ounces." Same issue as #2.
#5 is the expression for "The amount of water is not equal to eight ounces." This is the correct expression as the only information we know is that it's not eight ounces.
School OL ROC below
School of Rock
Guitar Bass Drums Keyboard Total
6th grade 13 10 17
20
60
7th Grade
14
17
11
10
8th Grade
18
12
17
16
63
Total
45
51
42
175
What percent of the 7th graders in the School of Rock play keyboard? Round your
answer to the nearest whole number percent,
Submit Anwwer
0
Using the percentage concept, it is found that 19% of the 7th graders in the School of Rock play keyboard.
The percentage of an amount a relative to another amount b is given by:
[tex]P = 100\frac{a}{b}[/tex]
From the table given:
There are 14 + 17 + 11 + 10 = 52 7th graders, hence, [tex]b = 52[/tex]Of those, 10 play the keyboard, hence [tex]a = 10[/tex]Then
[tex]P = 100\frac{a}{b} = 100\frac{10}{52} = 19[/tex]
19% of the 7th graders in the School of Rock play keyboard.
A similar problem is given at https://brainly.com/question/10491646
DIRECTIONS: Use this information to answer Parts A and B.
Home sold for $286,000. The amount the homeowner received, before taxes and closing costs, was the selling price minus the commission to the real estate agent, which was 6%.
Question 1
Part A
How much commission did the real estate agent earn on the sale?
Part B
How do you know your answer is reasonable?
Answer:
268,840
Step-by-step explanation:
286,000 x 6% commission= 17,160. you then subtract this commission from the sold price of 286000=$17160
A researcher is following the growth of a particular type of flower. She writes the given equation to show the height of the flower g(n), in inches, after n days.
g(n) = 10(1.02)n
What does the average rate of change of the function represent?
A.
the number of days flower grew
B.
the average height of the flower after 5 days
C.
the average growth of the flower from day 1 to day 5
D.
the average time it takes for the flower to grow from 1-5 inches
The expression given represents an exponential growth relation. The average rate of change is the average growth of the flower from day 1 to days 5
The rate of change of the flower can be deduced frommthe equation as :
1.02 - 1 = 0.02Hence, the growth rate of the flower per day = 0.02
The number of days, n = 5
Therefore, the average growth rate is the average growth of the flower within the number of days given.
Learn more : https://brainly.com/question/25449918
Answer:
C
Step-by-step explanation:
I got it right
How do I slove Solving Systems Using Matrices in word form like this please help I'm almost don't for the night >_< ;-; :( o-o
Answer:
Below!
Step-by-step explanation:
Old Faithful in Yellowstone National Park shoots water 60 feet into the air that casts a shadow of 42 feet. What is the height of a nearby tree that casts a shadow 63 feet long? Assume the triangles are similar.
Convert into an exponential expression
Answer:
Step-by-step explanation:
Rosie is mixing a special green paint which contains 2/3 cups yellow paint 1/3cups white paint 1 and 1/5 cups blue paint and last 1/5 black paint what percentage what percentage of the green paint is blue
Plzzzz help mee I forgot how to do it
Answer:
100011 is the base number.Step-by-step explanation:
Best of luck friendAnna starts a fixed deposit with $178000, the bank offers 9.5% per year simple interest for 8 months. she has the option of restarting the investment using the interest earned as principal or cashing out at the end of the 8 months, (A) Calculate the interest due after 8 months. (B) if she restarts the investment into a new one calculate the total value of the investment at the end of the second 8 months
Using simple interest, we have that:
A) The interest due after 8 months is $11,272.33.
B) The total value of the investment will be of $189,986.24.
The amount of interest earning using simple interest, after t years, with an yearly interest rate of i and an initial investment of P is given by:
[tex]E = Pit[/tex]
In this problem:
Deposit of $178,000, hence [tex]P = 178000[/tex].Interest rate of 9.5% per year, hence [tex]i = 0.095[/tex].8 months, the time is in years, hence [tex]t = \frac{8}{12} = \frac{2}{3}[/tex]Item a:
[tex]E = Pit[/tex]
[tex]E = 178000(0.095)\frac{2}{3} = 11272.33[/tex]
The interest due after 8 months is $11,272.33.
Item b:
For the second interest, we consider [tex]P = 11272.33[/tex], hence:
[tex]E_2 = Pit[/tex]
[tex]E_2 = 11272.33(0.095)\frac{2}{3} = 713.91[/tex]
The total value will be composed by:
The initial deposit of $178,000.The first interest of $11,272.33.The second interest of $713,91.Hence, it will be:
[tex]T = 178000 + 11272.33 + 713.91 = 189986.24[/tex]
The total value of the investment will be of $189,986.24.
A similar problem is given at https://brainly.com/question/13176347
Does the following relationship represent a function?
A. Yes
B. No
I NEED THE ANSWER ASAP. IM BEING TIMED
The following information is known about a savings account.
Time = 6 years
Interest rate = 1.9%
Principal = $850
What amount of total interest will be earned at the end of year 6?
Answer:
96.90
Step-by-step explanation:
I = PRT
T = 6
P = 850
I = 1.9% = 0.019
I = (850)(0.019)(6) = 96.90 <==
Q(x)=-1/2x-3; q(x)=-4
Help
Answer:4
Step-by-step explanation:
10 times 7 + 5^2/2 times 5
Answer:
132.5
Step-by-step explanation:
10x7=70
5^2=25
70+25/2x5
70+12.5x5
70+62.5=132.5