Intermediate Algebra (11th edition)

Find the perimeter of each triangle. Hint: For Exercise 125, use

Solve each problem.

127.The following letter appeared in the column “Ask Tom Why,” written by Tom Skilling of

the Chicago Tribune:

Dear Tom,

I cannot remember the formula to calculate the distance to the horizon. I have a

stunning view from my 14th-f loor condo, 150 ft above the ground. How far can I see?

Ted Fleischaker; Indianapolis, Ind.

Skilling’s answer was as follows:

To find the distance to the horizon in miles, take the square root of the height of

your view in feet and multiply that result by 1.224. Your answer will be the number of

miles to the horizon. (Source: Chicago Tribune.)

Assuming that Ted’s eyes are 6 ft above the ground, the total height from the ground is

ft. To the nearest tenth of a mile, how far can he see to the horizon?

128.The length of the diagonal of a box is given by

where L, W, and Hare, respectively, the length, width,

and height of the box. Find the length of the diagonal

Dof a box that is 4 ft long, 2 ft wide, and 3 ft high.

Give the exact value, and then round to the nearest

tenth of a foot.

129.A Sanyo color television, model AVM-2755, has a rec-

tangular screen with a 21.7-in. width. Its height is 16 in.

What is the measure of the diagonal of the screen, to the

nearest tenth of an inch? (Source:Actual measurements

of the author’s television.)

130.A formula from electronics dealing with the impedance of parallel resonant circuits is

where the variables are in appropriate units. Find Iif , , , and

. Give your answer to the nearest thousandth.
131.In the study of sound, one version of the law of tensions is

If F 1 = 300 , F 2 = 60 , and ƒ 2 = 260 , find ƒ 1 to the nearest unit.

ƒ 1 =ƒ 2

B

F 1

F 2

.

v= 120 p

E= 282 R= 100 L= 264

I=

E

2 R^2 +v^2 L^2

,

D= 2 L^2 +W^2 +H^2 ,

150 + 6 = 156

A 2 k+ 2 k= 22 k.B

452 CHAPTER 8 Roots, Radicals, and Root Functions

x

y

0

(−3, −3)

(2, 6)

(6, 2)

x

y

0

(1, 3)

(1, −2)

(−2, −4)

L

H

W

D

16 in.

21.7 in.

d