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