An indoor track is made up of a rectangular region with two semi-circles at the ends. The distance around the track is 400 meters. What dimensions for the rectangular region maximize the area of the rectangular region?

Answers

Answer 1

Answer:

width of rectangle = 2R = (200/π) = 400/π meters

length of rectangle = 400 - π(200/π) = 400 - 200 = 200 meters

Step-by-step explanation:

The distance around the track (400 m) has two parts:  one is the circumference of the circle and the other is twice the length of the rectangle.

Let L represent the length of the rectangle, and R the radius of one of the circular ends.  Then the length of the track (the distance around it) is:

Total = circumference of the circle + twice the length of the rectangle, or

         =                    2πR                    + 2L    = 400 (meters)  

This equation is a 'constraint.'  It simplifies to πR + L = 400.  This equation can be solved for R if we wish to find L first, or for L if we wish to find R first.  Solving for L, we get L = 400 - πR.

We wish to maximize the area of the rectangular region.  That area is represented by A = L·W, which is equivalent here to A = L·2R = 2RL.  We are to maximize this area by finding the correct R and L values.

We have already solved the constraint equation for L:  L = 400 - πR.  We can substitute this 400 - πR for L in

the area formula given above:    A = L·2R = 2RL = 2R)(400 - πR).  This product has the form of a quadratic:  A = 800R - 2πR².  Because the coefficient of R² is negative, the graph of this parabola opens down.  We need to find the vertex of this parabola to obtain the value of R that maximizes the area of the rectangle:        

                                                                   -b ± √(b² - 4ac)

Using the quadratic formula, we get R = ------------------------

                                                                            2a

                                                   -800 ± √(6400 - 4(0))           -1600

or, in this particular case, R = ------------------------------------- = ---------------

                                                        2(-2π)

            -800

or R = ----------- = 200/π

            -4π

and so L = 400 - πR (see work done above)

These are the dimensions that result in max area of the rectangle:

width of rectangle = 2R = (200/π) = 400/π meters

length of rectangle = 400 - π(200/π) = 400 - 200 = 200 meters


Related Questions

Hi, I got 8 points off on this problem, can you help me figure out what I did wrong?

Answers

Answer:

Possible errors: Triangle classification and definition.

Step-by-step explanation:

An isoceles triangle has at least two congruent sides of the same length.  

Given the triangle that has two equal angles, and that you'll have to prove that the triangle also has two equal sides.  

Using the Converse of Isoceles Triangle Theorem, where it states that if a triangle has two congruent angles < PQR ≅ < PRQ, for which opposite sides of those angles are congruent:  

The opposite side of <PQR is line PR.The opposite side of <PRQ is line PQ.  

Additionally, connecting point P to point X along the line QR such that PX ⊥ QR, divides △PQR into two symmetrical sections, where points Q and R are equidistant from point X.      

Answer:

Possible errors: Triangle classification and definition.

select all the ways you can describe the given polygon

Answers

Answer:

Isoceles and obtuse

Step-by-step explanation:

Write and then evaluate an expression for the following number line.

Answers

Answer:

Step-by-step explanation:

‏The result of a division problem is the a ) divisor . b ) quotient . c ) factor . d ) remainder .

Answers

Answer:

b) quotient

Step-by-step explanation:

divisor is the number/value you are dividing with.

A remainder is a number that remains after you divide.

A factor is a number that can divide into a number or numbers without leaving a remainder

what are the relationships between inscribed, central, and circumscribed angles of a circle?

Answers

Answer:

Topics include the relationship between central, inscribed, and circumscribed angles; inscribed angles on a diameter are right angles; the radius of a circle is perpendicular to the tangent where the radius intersects the circle. Common Core: HSG-C.A.2

Step-by-step explanation:

PA BRAINLIEST

solve pls brainliest

Answers

Answer:

Mixed number: 5(1/10)

Improper fraction: (51/10)

Step-by-step explanation:

Hope this helps!

Answer:

Mixed number: 5 1/10 and improper fraction: 52/10

(3[tex]x^{2}[/tex]+[tex]y^{2}[/tex])Y+([tex]y^{2}[/tex]-[tex]x^{2}[/tex])x×[tex]\frac{dy}{dx}[/tex]=0

Answers

It looks like the given differential equation is

(3x² + y²) y + (y² - x²) x dy/dx = 0

Multiply both sides by 1/x³ to get

(3 + y²/x²) y/x + (y²/x² - 1) dy/dx = 0

(Note that in order to do this, we must have x ≠ 0, which means that if a solution exists, it would have to be on either (-∞, 0) or (0, ∞).)

Now substitute z = y/x, or y = xz, from which we get dy/dx = x dz/dx + z. Making this replacement and simplifying yields a separable equation:

(3 + z²) z + (z² - 1) (x dz/dx + z) = 0

(3 + z²) z + (z² - 1) x dz/dx + (z² - 1) z = 0

(z² - 1) x dz/dx = -(2z³ + 2z)

x dz/dx = (2z³ + 2z)/(1 - z²)

(1 - z²)/(2z (z² + 1)) dz = dx/x

Integrate both sides. On the left, split up the expression into partial fractions.

[tex]\dfrac{1-z^2}{z(z^2+1)} = \dfrac az + \dfrac{bz+c}{z^2+1}[/tex]

[tex]\dfrac{1-z^2}{z(z^2+1)} = \dfrac{a(z^2+1)+(bz+c)z}{z(z^2+1)}[/tex]

[tex]1-z^2 = (a+b)z^2 + cz + a[/tex]

for which we find a = 1, b = -2, and c = 0:

[tex]\dfrac{1-z^2}{2z(z^2+1)} = \dfrac12 \left( \dfrac1z - \dfrac{2z}{z^2+1} \right)[/tex]

Integrating and simplifying yields

1/2 ∫ (1/z - 2z/(z² + 1)) dz = ∫ dx/x

1/2 (ln|z| - ln(z² + 1)) = ln|x| + C

1/2 ln|z / (z² + 1)| = ln|x| + C

ln(√(z/(z² + 1))) = ln|x| + C

exp[ln(√(z/(z² + 1)))] = exp[ln|x| + C]

√(z/(z² + 1)) = exp[ln|x|] exp[C]

√(z/(z² + 1)) = Cx

z/(z² + 1) = Cx²

Replacing z = y/x then gives us an implicit solution of

(y/x) / (y²/x² + 1) = Cx²

xy / (y² + x²) = Cx²

y / (y² + x²) = Cx

y = Cx (y² + x²)

Cxy² - y + Cx³ = 0

though we can solve for y explicitly (assuming x > 0) using the quadratic formula to end up with

y = (1 + √(1 - Cx⁴))/(Cx)

(the other solution only differs by the sign on the square root)

Solve the system of equations by the addition method.
2x - 5y = 4
7x - 2y = 4


Type in ordered pair.

Answers

Answer:

0.400

Step-by-step explanation:

Slope = 0.800/2.000 = 0.400

 x-intercept = 4/2 = 2

 y-intercept = 4/-5 = -0.80000

Type the correct answer in the box. Use numerals instead of words. If necessary, use / for the fraction bar.

If a submarine dives 378 feet in 14 seconds, the average change in elevation is feet per second.

Answers

Answer:

27 feet per second.

Step-by-step explanation:

You already have your time unit in second and length measurement in feet so just divide the two 378/14=27 feet per second.

Answer:

-27 feet per second

Step-by-step explanation:

378 ÷ 14 = 27

because the submarine is going down, the sign has to be negative

Write the following complex number in rectangular form. 6(cos π/ 4+ isin π/ 4)
6(cos π/ 4 + i sin π/ 4) =
​(Simplify your answer. Type an exact​ answer, using radicals as needed. Use integers or fractions for any numbers in the expression. Type your answer in the form a+bi. Rationalize all​ denominators.)

Answers

[tex]\stackrel{\textit{complex form}}{\stackrel{\stackrel{r}{\downarrow }}{6}\left[ \cos\left( \frac{\pi }{4} \right) +i\sin\stackrel{\stackrel{\theta }{\downarrow }}{\left( \frac{\pi }{4} \right)} \right]}\implies 6\left[ \frac{\sqrt{2}}{2}+i\frac{\sqrt{2}}{2} \right]\implies \cfrac{6\sqrt{2}}{2}+i\cfrac{6\sqrt{2}}{2} \\\\[-0.35em] ~\dotfill\\\\ ~\hfill \stackrel{\textit{rectangular form}}{\stackrel{\stackrel{a}{\downarrow }}{3\sqrt{2}}+\stackrel{\stackrel{b}{\downarrow }}{3\sqrt{2}}i}~\hfill[/tex]

Gayla’s mom bought 9.5 gallons of gas for $21.85 . What is the cost of a gallon of gas?

Answers

Answer:

$2.30

Step-by-step explanation:

True / False: ANOVA, Part I. Determine if the following statements are true or false in ANOVA, and explain your reasoning for statements you identify as false.
(a) As the number of groups increases, the modified significance level for pairwise tests increases as well.
(b) As the total sample size increases, the degrees of freedom for the residuals increases as well.
(c) The constant variance condition can be somewhat relaxed when the sample sizes are relatively consistent across groups.
(d) The independence assumption can be relaxed when the total sample size is large.

Answers

The answer is B hope that helps

Answer this please not links-

Answers

Answer:

I believe it's 9 hope this helps

What is 1/3÷1/2 math answers?

Answers

Answer:

= [tex]\frac{2}{3}[/tex]

Step-by-step explanation:

Result in decimals: 0.66666666666667

x = mutiply

[tex]=\frac{1}{3} x\frac{2}{1}[/tex]

[tex]\frac{1 x 2}{3 x 1 }[/tex]

= [tex]\frac{2}{3}[/tex]

(Hope this helps can I pls have brainlist (crown)☺️)

At Sidney's Hats, 84% of the 50 hats are baseball caps. How many baseball caps are there?

Answers

Answer:

thats what i said

Step-by-step explanation:

42 baseball caps

Since 84% = 84/100 , and 50 is 1/2 of 100 we can think of 84% of 50 being half of the value of 84% of 100. So 84/2 = 42

There are other ways of solving such as multiplying 50 by 0.84, however I believe that how I solved it was the easiest way for this specific problem :)


what is x over 5 = -3 find x value

Answers

5*-3=-15

x=-15

hope this helps

Answer:

x = -15

Step-by-step explanation:

[tex]\frac{x}{5}=-3~(Given)\\\\5(\frac{x}{5})=5(-3)~(Multiply~5~on~both~sides)\\\\x=-15~(Simplify)[/tex]

Change 41/7 from an improper fraction to a mixed number.

Answers

Answer:

5 6/7

Step-by-step explanation:

how many times does 7 go onto 41?

7 x 5 = 35

remainder is 6 so;

5 6/7

Hey there!

41/7

= (5 * 7 + 6)/7

= (5 * 7)/7 + 6/7

= 5 6/7

= 5 6/7 ≈ 41/7

Therefore, your answer is: 5 6/7

Good luck on your assignment and enjoy your day’

~Amphitrite1040:)

A teacher selects 4 students from her class of 37 to work together on a project. How many ways are there for her to select the students

Answers

Answer:

The correct answer is 66,045

show how the work is done and help and have to be fast with math

Answers

Answer:

Answer is 14

Step-by-step explanation:

By understanding the concept of math

Answer: you mom

Step-by-step explanation:

Someone please help...I hate IXL smh

Answers

Answer:

The slope is 10.

Step-by-step explanation:

It starts at 30, then 40, then 50 and so on so forth.

That being said the answer is 10.

Also, I hate IXL as well, but, I hope I helped.

Let me know if I got it correct.

- Abigail (:

y=x+30 is the equation of the line in slope intercept form.

The slope intercept form of a line is y=mx+b, where m is slope and b is the y intercept.

The slope of line passing through two points (x₁, y₁) and (x₂, y₂) is

m=y₂-y₁/x₂-x₁

The points through which the line passes is (0,30) and (20,50).

Slope = 50-30/20-0

=20/20

=1

Now let us find the y intercept.

Let us consider any point (0, 30).

30=1(0)+b

b=30

Hence, y=x+30 is the equation of the line in slope intercept form.

To learn more on slope of line click:

https://brainly.com/question/16180119

#SPJ6

what is -2(x+1) simplified

Answers

Answer:

-2x - 2

Step-by-step explanation:

-2(x + 1)

[tex](-2)(x+1)[/tex] [tex](-2)(x)+(-2)(1)[/tex] [tex]-2x - 2[/tex]

Therefore, the answer is -2x - 2.

Answer:

-2x - 2

Step-by-step explanation:

Simplify:

-2(x+1)-2(x) + -2(1)-2x - 2

-Chetan K

See attached question

Answers

Answer:

Its 34 times 87

Step-by-step explanation:

34 times 87 is 2958

The area under the graph line
made with the x-axis represents
the change in position of the
object on a velocity versus time
graph. (5 points)

Answers

The statement is true: the area under the graph line made with the x-axis

represents the change in position of the object on a velocity versus time

graph.

Reasons:

[tex]\displaystyle Velocity = \frac{Dislacement}{Time}[/tex]

The area under the velocity time graph is given by the integration of the function for the velocity over the time interval.

A constant velocity is an horizontal line and the integration of a constant with time, gives the product of time and the constant, which is area under the rectangular graph.

Therefore, the area under the graph line made with the x-axis represents the change in position of the object on a velocity versus time graph.

Learn more here:

https://brainly.com/question/18910091

Answer: True

Step-by-step explanation:

Evaluate 4x squared - 8x + 8 when x = -6

Answers

Answer:

44

Step-by-step explanation:

√4×-6+8×6+8=2×-6+48+8

-12+48+8

=48

Hey there!

4x^2 - 8x + 8

= 4(-6)^2 - 8(-6) + 8

= 4(6)(6) - 8(-6) + 8

= 4(36) - (-48) + 8

= 144 - (-48) + 8

= 144 + 48 + 8

= 192 + 8

= 200

Therefore, your answer is: 200

Good luck on your assignment and enjoy your day!

~Amphitrite1040:)

If Clare takes out a mortgage for 22 years at an interest rate of 3% and her monthly repayments are $984, what is the principal loan amount?

Answers

Using simple interest, it is found that the principal loan amount was of $156,491.6.

The amount of money after t years in simple interest is modeled by:

[tex]A(t) = A(0)(1 + rt)[/tex]

In which:

A(0) is the initial amount, which is also called principal. r is the interest rate, as a decimal.

In this problem, she paid $984 monthly for 22 years, hence:

[tex]t = 22, A(t) = 984(22)(12) = 259776[/tex]

Interest rate of 3%, hence [tex]r = 0.03[/tex]

Then:

[tex]A(t) = A(0)(1 + rt)[/tex]

[tex]259776 = A(0)[1 + 0.03(22)][/tex]

[tex]A(0) = \frac{259776}{1 + 0.03(22)}[/tex]

[tex]A(0) = 156491.6[/tex]

The principal loan amount was of $156,491.6.

A similar problem is given at https://brainly.com/question/13176347

On the first three tests, Jhon scored 72 points. On the next test, he got a higher score. On the
third test, his score was 1 more than on the second. His average on the three tests was 83.
What were his grades on the second and third tests?

Answers

Answer:

Second test=88

Third test=89    Hope this helps please mark brainliest it helps a lot! Thanks!

Step-by-step explanation:

According to the question, here we got to know that John scored 72 points in the first test

In the second he scored higher than the 1st test

In the third he scored 1 mark more than the second test

His average in the three tests was 83

So,

Let's the marks scored in the 2nd test be x

Hence, in the third test he got x + 1

Average is 83

[tex] \frak{Average = \frac{{1}^{st} \: test + {2}^{nd} \: test + {3}^{rd} \: test }{3} } \\ \\ \dashrightarrow \frak{83 = \frac{72 + x + x + 1}{3}} \\ \\ \dashrightarrow \frak{83 = \frac{73 + 2x}{3}} \\ \\ \dashrightarrow \frak{249 = 73 + 2x } \\ \\ \dashrightarrow \frak{249 - 73 = 2x} \\ \\ \dashrightarrow \frak{249 = 73 + 2x } \\ \\ \dashrightarrow \frak{x = \frac{176}{2} } \\ \\ \dashrightarrow \frak{249 = 73 + 2x } \\ \\ \dashrightarrow \frak{249 - 73 = 2x} \\ \\ \dashrightarrow \frak{249 = 73 + 2x } \\ \\ \star \qquad \boxed{ \green{\frak{x = 88}}} \\ \\ \sf{ \underline{{2}^{nd} \: test }} : \\ \\ \boxed{ \red{88}} \\ \\ \sf{ \underline{{3}^{rd} \: test }} : \\ \\ \rightarrow x + 1 \\ \\ \rightarrow 88 + 1 \\ \\ \boxed{ \red{ 89 }}[/tex]

The temperature of a substance in an experiment changes by −8.7°F from 10 a.m. to 1 p.m. At 5 p.m., the temperature is 33.5°F. It is 23 of what the temperature was at 1 p.m.

What was the temperature at 10 a.m. of the substance?

Enter your answer as a decimal in the box.

°F

Answers

Answer: 33.5

Step-by-step explanation:

the answer is: 58.95

i took the test

For a function to be inverse, it must be

Answers

Answer:

look at the explanation

Step-by-step explanation:

for f(x) and g(x) to be inverse,

f(g(x))=g(f(x))=x

the length of a rectangle is 3 more than 3 times it’s width. the perimeter of the rectangle is 174 inches. what is the length of the rectangle?

Answers

Answer:

66 anches beacause i don't know

Step-by-step explanation:

Quick Computing installed its previous generation of computer chip manufacturing equipment 3 years ago. Some of that older equipment will become unnecessary when the company goes into production of its new product. The obsolete equipment, which originally cost $40 million, has been depreciated straight-line over an assumed tax life of 5 years, but it can be sold now for $18 million. The firm’s tax rate is 35%. What is the after-tax cash flow from the sale of the equipment?

Answers

The company's after-tax cash flow is a measure of the company's cash

generation ability.

The after-tax cash flow from the sale of the equipment is $16.1 million

Reasons:

The given parameter are;

Original cost of the equipment = $40 million

The type of depreciation = Straight line depreciation

Number of years of depreciation = 5 years

Current price at which it can be sold = $18 million

The tax rate of the firm = 35%

Required:

The after-tax cash flow from the sale of the equipment.

Solution:

The Cash Flow After Tax, CFAT, is given as follows;

CFAT = Net income + Amortization  + Depreciation  + Other non-Cash Cash Charges

The annual depreciation is given as follows;

[tex]Annual \ depreciation = \dfrac{\$40 \ million - \$18 \ million}{5 \ years} = \$4.4 \ million \ per \ year[/tex]

Selling the equipment gives;

The Earnings Before Tax (EBT) = $18 million

The Net Income = Income - Tax = $18 million - (35% × $18 million)

The Net Income = $11.7 million

Cash Flow After Tax CFAT = Net income + Depreciation

∴ CFAT = $11.7 million + $4.4 million = $16.1 million

The after-tax cash flow = $16.1 million

Learn more here:

https://brainly.com/question/15057869

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