# To find the maximum distance from top of a building at height h using the function D ( h ) = 2 r h + h 2 .

### Precalculus: Mathematics for Calcu...

6th Edition
Stewart + 5 others
Publisher: Cengage Learning
ISBN: 9780840068071

### Precalculus: Mathematics for Calcu...

6th Edition
Stewart + 5 others
Publisher: Cengage Learning
ISBN: 9780840068071

#### Solutions

Chapter 2.1, Problem 72E

a.

To determine

Expert Solution

## Answer to Problem 72E

The distance value from top of a building at height h=0.1 is D(0.1)=28.1427miles and h=0.2 is D(0.2)=39.8miles .

### Explanation of Solution

Given: Distance equation D(h)=2rh+h2 and r=3960mi .

Plug r=3960 in D(h)=2rh+h2

D(h)=2(3960)h+h2D(h)=7920h+h2

Calculation:

Plug h=0.1 and h=0.2 in D(h)=7920h+h2

D(0.1)=7920(0.1)+(0.1)2D(0.1)=28.1427miles

D(0.2)=7920(0.2)+(0.2)2D(0.2)=39.8miles

Thus, the distance value from top of a building at height h=0.1 is D(0.1)=28.1427miles and h=0.2 is D(0.2)=39.8miles .

b.

To determine

Expert Solution

## Answer to Problem 72E

The distance from the deck of Toronto’s CN tower 1135ft above the ground is D(0.215)=41.262miles .

### Explanation of Solution

Given: Height above the ground at 1135ft .

Let 1 ft equals to 0.000189394miles .Then

1135ft equals to:

1135(0.000189394)=0.215miles

Calculation:

Plug h=0.215 in D(h)=7920h+h2

D(0.215)=7920(0.215)+(0.215)2D(0.215)=41.262miles

Thus, the distance from the deck of Toronto’s CN tower 1135ft above the ground is D(0.215)=41.262miles .

c.

To determine

Expert Solution

## Answer to Problem 72E

the distance that pilot can see from commercial aircraft fly at an altitude of about 7 miles is D(7)=235.56miles .

### Explanation of Solution

Given: Altitude value at

7miles .

Calculation:

Plug h=7 in D(h)=7920h+h2

D(7)=7920(7)+(7)2         =235.56miles

Hence, the distance that pilot can see from commercial aircraft fly at an altitude of about 7 miles is D(7)=235.56miles .

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