Chapter 1

College Algebra with Modeling and Visualization · 344 exercises

Problem 25

Evaluate by hand. $$ \frac{4+9}{2+3}-\frac{-3^{2} \cdot 3}{5} $$

5 step solution

Problem 25

Complete the following. (a) Find \(f(x)\) for the indicated values of \(x\), if possible. (b) Find the domain of \(f\). $$ f(x)=6-3 x \text { for } x=-1, a+1 $$

3 step solution

Problem 26

Find the exact distance between the two points. Where appropriate, also give approximate results to the nearest hundredth. $$ (40,6),(-20,17) $$

8 step solution

Problem 26

State the slope of the graph of \(f\). Interpret this slope. $$ f(x)=\frac{2}{3} x $$

3 step solution

Problem 26

Evaluate by hand. $$ 10 \div 2 \div \frac{5+10}{5} $$

4 step solution

Problem 26

Complete the following. (a) Find \(f(x)\) for the indicated values of \(x\), if possible. (b) Find the domain of \(f\). $$ f(x)=\frac{3 x-5}{x+5} \text { for } x=-1, a $$

3 step solution

Problem 27

Find the exact distance between the two points. Where appropriate, also give approximate results to the nearest hundredth. $$ (a, 0),(0,-b) $$

5 step solution

Problem 27

State the slope of the graph of \(f\). Interpret this slope. $$ f(x)=-5 $$

4 step solution

Problem 27

Evaluate by hand. $$ -5^{2}-20 \div 4-2 $$

4 step solution

Problem 28

State the slope of the graph of \(f\). Interpret this slope. $$ f(x)=x+5 $$

3 step solution

Problem 28

Evaluate by hand. $$ 5-(-4)^{3}-(4)^{3} $$

4 step solution

Problem 28

Complete the following. (a) Find \(f(x)\) for the indicated values of \(x\), if possible. (b) Find the domain of \(f\). $$ f(x)=x^{2}-x+1 \text { for } x=1,-2 $$

3 step solution

Problem 29

An isosceles triangle has at least two sides of equal length. Determine whether the triangle with vertices \((0,0),(3,4),(7,1)\) is isosceles.

4 step solution

Problem 29

State the slope of the graph of \(f\). Interpret this slope. $$ f(x)=9-x $$

3 step solution

Problem 29

Write the number in scientific notation. \(184,800\) (New lung cancer cases reported in 2005 )

4 step solution

Problem 29

Complete the following. (a) Find \(f(x)\) for the indicated values of \(x\), if possible. (b) Find the domain of \(f\). $$ f(x)=\frac{1}{x^{2}} \text { for } x=4,-7 $$

3 step solution

Problem 30

An equilateral triangle has sides of equal length. Determine whether the triangle with vertices \((-1,-1),(2,3),(-4,3)\) is equilateral.

4 step solution

Problem 30

State the slope of the graph of \(f\). Interpret this slope. $$ f(x)=23 $$

4 step solution

Problem 30

Write the number in scientific notation. \(29,285,000\) (People worldwide living with HTV)

3 step solution

Problem 30

Complete the following. (a) Find \(f(x)\) for the indicated values of \(x\), if possible. (b) Find the domain of \(f\). $$ f(x)=\sqrt{x-3} \text { for } x=4, a+4 $$

3 step solution

Problem 31

At 9: 00 A.M. car \(A\) is traveling north at 50 miles per hour and is located 50 miles south of car \(\mathbf{B}\). Car \(\mathbf{B}\) is traveling west at 20 miles per hour. (a) Let \((0,0)\) be the initial coordinates of car \(\mathbf{B}\) in the \(x y\) -plane, where units are in miles. Plot the locations of each car at 9: 00 A.M. and at 11: 00 A.M. (b) Find the distance \(d\) between the cars at 11: 00 A.M.

3 step solution

Problem 31

Write the number in scientific notation. 0.04361 (Proportion of U.S. deaths attributed to accidents in 2004 )

5 step solution

Problem 31

Complete the following. (a) Find \(f(x)\) for the indicated values of \(x\), if possible. (b) Find the domain of \(f\). $$ f(x)=\frac{1}{x^{2}-9} \text { for } x=4, a-5 $$

3 step solution

Problem 32

Two ships leave a harbor at the same time. The first ship heads north at 20 miles per hour, and the second ship heads west at 15 miles per hour. Write an expression that gives the distance \(d\) between the ships after \(t\) hours.

6 step solution

Problem 32

Write the number in scientific notation. 0.62 (Number of miles in 1 kilometer)

5 step solution

Problem 33

Use the midpoint formula for the following. The average life expectancy for a female born in the United States was 77.4 years in 1980 and 79.5 years in 2000 . Estimate the average life expectancy for a female born in 1990 . (Actual life expectancy was \(78.8 .\) ) (Source: Bureau of the Census.)

4 step solution

Problem 33

The function given by \(P(x)=19.4 x\) calculates the pounds of \(\mathrm{CO}_{2}\) (carbon dioxide) released into the atmosphere by a car burning \(x\) gallons of gasoline. (a) Calculate \(P(20)\) and interpret the result. (b) Find the slope of the graph of \(P\). Interpret this slope as a rate of change.

3 step solution

Problem 33

Write the number in scientific notation. $$ 2450 $$

4 step solution

Problem 34

Use the midpoint formula for the following. In 1990 there were \(773,919\) inmates in state and federal prisons, and in 2000 there were \(1,391,892 .\) Estimate the number of inmates in 1995\. (Actual number was \(1,125,874\).) (Source: Department of Justice.)

5 step solution

Problem 34

The distance \(D\) in miles that a train is from a station after \(x\) hours is given by the formula \(D(x)=150-20 x\) (a) Calculate \(D(5)\) and interpret the result. (b) Find the slope of the graph of \(D .\) Interpret this slope as a rate of change.

4 step solution

Problem 34

Write the number in scientific notation. $$ 105.6 $$

3 step solution

Problem 34

Complete the following. (a) Find \(f(x)\) for the indicated values of \(x\), if possible. (b) Find the domain of \(f\). $$ f(x)=\frac{1}{\sqrt{x-1}} \text { for } x=0, a^{2}-a+1 $$

3 step solution

Problem 35

In the Olympic Games, the 200 -meter dash is run in approximately 20 seconds. Estimate the time to run the 100 -meter dash.

5 step solution

Problem 35

A driver's distance \(D\) in miles from a rest stop after \(x\) hours is given by \(D(x)=75 x\) (a) How far is the driver from the rest stop after 2 hours? (b) Find the slope of the graph of \(D .\) Interpret this slope as a rate of change.

4 step solution

Problem 35

Write the number in scientific notation. $$ 0.56 $$

3 step solution

Problem 36

The median age of the U.S. population for each year \(t\) between 1970 and 2010 can be approximated by the formula \(A(t)=0.243 t-450.8\). (a) Compute the median ages in 1980 and 2000 . (b) What is the slope of the graph of \(A ?\) Interpret the slope.

4 step solution

Problem 36

Between any two real numbers \(a\) and \(b\) there is always another real number. How could such a number be found?

5 step solution

Problem 36

Write the number in scientific notation. $$ -0.00456 $$

5 step solution

Problem 37

A car's distance from a service center along a straight highway can be described by a constant function of time. What can be said about the car's velocity?

4 step solution

Problem 37

Find the midpoint of the line segment connecting the points. $$ (1,2),(5,-3) $$

5 step solution

Problem 37

Write the number in scientific notation. $$ -0.0087 $$

4 step solution

Problem 38

Find the midpoint of the line segment connecting the points. $$ (-6,7),(9,-4) $$

5 step solution

Problem 38

Write the number in scientific notation. $$ 1,250,000 $$

5 step solution

Problem 39

Determine if \(f\) is a linear or nonlinear function. If \(f\) is a linear function, determine if \(f\) is a constant function. Support your answer by graphing \(f\). $$ f(x)=-2 x+5 $$

4 step solution

Problem 39

Find the midpoint of the line segment connecting the points. $$ (-30,50),(50,-30) $$

3 step solution

Problem 39

Write the number in scientific notation. $$ 206.8 $$

4 step solution

Problem 40

Determine if \(f\) is a linear or nonlinear function. If \(f\) is a linear function, determine if \(f\) is a constant function. Support your answer by graphing \(f\). $$ f(x)=3 x-2 $$

3 step solution

Problem 40

Find the midpoint of the line segment connecting the points. $$ (28,-33),(52,38) $$

5 step solution

Problem 40

Write the number in scientific notation. $$ 0.00007 $$

4 step solution

Problem 41

Determine if \(f\) is a linear or nonlinear function. If \(f\) is a linear function, determine if \(f\) is a constant function. Support your answer by graphing \(f\). $$ f(x)=1 $$

3 step solution

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