The opening of a tunnel that travels through a mountainside can be modeled by [tex]y = - \frac {2}{15} (x - 15)(x + 15)[/tex], where x and y are measured in feet. The x-axis represents the ground.
​a. Find the width of the tunnel at ground level.
b. How tall is the tunnel?

Answers

Answer 1

Answer:

(a) 30 feet

(b) 30 feet.

Step-by-step explanation:

Given that the opening of a tunnel that travels through a mountainside can be modeled by

[tex]y=\frac{-2}{15} (x-15)(x+15)[/tex], where x and y are measured in feet.

[tex]\Rightarrow y=\frac{-2}{15}(x^2-15^2}[/tex]

[tex]\Rightarrow y=\frac{-2}{15}{x^2-225}\cdots(i)[/tex]

(a) At the ground level, [tex]y=0[/tex]

So, the width of the tunnel at ground level is distance between the extreme point of the tunnel on the grount.

For, [tex]y=0[/tex], the extreme points of the tunnel.

[tex]0=\frac{-2}{15} (x-15)(x+15)[/tex]

[tex]\Rightarrow (x-15)(x+15) =0[/tex]

[tex]\Rightarrow x= 15, -15[/tex]

So, the extreme points of the tunnel are, [tex]x_1=15[/tex] and [tex]x_2=-15[/tex].

Hence, the width of the tunnel at the ground level

[tex]= | x_1 - x_2 |[/tex]

[tex]=|15-(-15)|[/tex]

[tex]=30[/tex] feet.

(b) The maximum height of the tunnel can be determiment by determining the maxima of the given function.

First determining the value of x for which the slope of the graph is zero.

[tex]\frac{dy}{dx}=0[/tex]

From equation (i),

-2x=0

[tex]\Rightarrow x=0[/tex]

And  [tex]\frac{d^2y}{dx^2}= -2[/tex]

which is always negative, so at x=0 the value of y is maximum.

Again, put x=0 in equation (i), we have

[tex]y=\frac{-2}{15}{0^2-225}[/tex]

[tex]\Rightarrow y=30[/tex] feet.

Hence, the tunnel is 30 feet tall.


Related Questions

Which difference is closest to 12?
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B. 67−19
C. 1516−38
D. 35−611

Answers

Answer:

b

The rest are at least 500 numbers away from 12

Step-by-step explanation:

What is the value of x in the equation x*3 = 27 512 ?

Answers

Answer:
9,170.67

Explanation:
27,512 divided by 3 = 9,170.67
X=3

New equation:
9,170.67 * 3 = 27,512
Sorry if this is wrong

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Answers

Answer:

B

Step-by-step explanation:

what is the answer a, b, c, or d

Answers

Answer: Choice B

(-2, 5)

==================================================

Explanation:

The original system is

[tex]\begin{cases}-4x+3y = 23\\ x-y = -7\end{cases}[/tex]

Multiply both sides of the second equation by 3. Doing so leads to this updated system of equations

[tex]\begin{cases}-4x+3y = 23\\ 3x-3y = -21\end{cases}[/tex]

Now add straight down

The x terms add to -4x+3x = -1x = -x

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We end up with the equation  -x = 2 which solves to x = -2

Now use this to find y. You can pick any equation with x,y in it

----------------

-4x+3y = 23

-4(-2)+3y = 23

8+3y = 23

3y = 23-8

3y = 15

y = 15/3

y = 5

Or

x-y = -7

-2-y = -7

-y = -7+2

y = -5

y = 5

Either way, we get the same y value.

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Write sec 325° in terms of the secant of'a positive acute angle.

Answers

Answer:

sec35°

Step-by-step explanation:

sec325° = sec(360 - 325)° = sec35°

The secant of a positive acute angle of sec 325° = sec 35° = 1.22077

What are Trigonometric Ratios?

Trigonometry values are all about the study of standard angles for a given triangle with respect to trigonometric ratios.The six trigonometric ratios are sine (sin), cosine (cos), tangent (tan), cotangent (cot), cosecant (cosec), and secant (sec).

Given data ,

The trigonometric ratio is = sec 325°

Now , to express the ratio in terms of a positive acute angle , we take the four quadrants of the graph and express the angle in the first quadrant.

And , 325° lies on the 4th Quadrant , where all cosines and secants are positive.

Therefore , sec 325° = sec ( 360° - 35° )

                                  = sec ( 35° )

                                  =1.22077

Hence , the secant of a positive acute angle of sec 325° = sec 35° = 1.22077

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3b) Two pizzas are made to the same dimensions. The only difference is that
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Step-by-step explanation:

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Step-by-step explanation:

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Step-by-step explanation:

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Answers

Answer:

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Step-by-step explanation:

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Answers

Answer:

900

Step-by-step explanation:

100 x 9 = 900

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Answer:

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Step-by-step explanation:

10*10=100

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Answers

Answer:

Jenny will owe her sister $9.30

Step-by-step explanation:

Subtract the money she earned from her dad from what she borrowed from her sister. $25.63-$16.33=$9.30 :)

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Answer:

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Step-by-step explanation:

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Answers

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Answers

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Step-by-step explanation: did you really need this?

A math test had 26 questions. The questions were either true/false or multiple choice. The true/false questions were worth 2 points each and the multiple choice were worth 5 points each. If the test is worth 100 points, how many of each type of question are included on the test?

Answers

Answer:

True/ false type 10 questions

Multiple choice type 16 questions  

Step-by-step explanation:

Using the given formation we can make equations to solve for the number of questions of either type is to be included

let the no of true/false be =x

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2x - 5x + 130 = 100

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y =26-10=16

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The answer would be less than because 4.24 x 10^6 is lesser than 3.28x10^6 so the answer is

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1 true

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Answers

Let's solve your equation step-by-step.

−3−9.25+m=0

Step 1: Simplify both sides of the equation.

−3−9.25+m=0

−3+−9.25+m=0

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The distance between the Sun and each planet in our solar system varies because the planets travel in elliptical (oval) orbits around the Sun rather than completely circular ones.

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Answers

Answer:

Hope this helps

Step-by-step explanation:

They describe how (1) planets move in elliptical orbits with the Sun as a focus, (2) a planet covers the same area of space in the same amount of time no matter where it is in its orbit, and (3) a planet's orbital period is proportional to the size of its orbit (its semi-major axis)

Answer:

because

Step-by-step explanation:

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Answers

Answer:

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A bowl contains 5 blue marbles, 2 yellow marbles, 10 black marbles, and 3 white marbles. Without
looking, what is the probability that Fiona pulls out a marble that is not white?

Answers

Answer:

85%

Step-by-step explanation:

The probability that Fiona pulls out a marble that is not white from a  bowl which contains 5 blue marbles, 2 yellow marbles, 10 black marbles, and 3 white marbles is 17/20.

What is the probability of an event?

Probability of an event is the ratio of number of favorable outcome to the total number of outcome of that event.

As the probability of an event can not be more than the number 1. Thus the probability of failure of a event is equal to the difference of the 1 to the success of the event.

A bowl contains 5 blue marbles, 2 yellow marbles, 10 black marbles, and 3 white marbles.  The total number of marbles in the bowl is,

[tex]n=5+2+10+3\\n=20[/tex]

The number of white balls in the bowl is 3. Thus, the probability that Fiona pulls out a marble that is white, is,

[tex]P=\dfrac{3}{20}[/tex]

The probability that Fiona pulls out a marble that is not white is,

[tex]P^{-1}=1-\dfrac{3}{20}\\P^{-1}=\dfrac{20-3}{20}\\P^{-1}=\dfrac{17}{20}[/tex]

Thus, the probability that Fiona pulls out a marble that is not white from a  bowl which contains 5 blue marbles, 2 yellow marbles, 10 black marbles, and 3 white marbles is 17/20.

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CAN SOME ONE HELP ME ASAP

Answers

Answer:

B

Step-by-step explanation:

1/5 is larger than 1/10

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if it did pls mark brainliest if possible

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