Chapter 10
Algebra for College Students · 388 exercises
Problem 59
Explain how to determine \(\log _{4} 76\) without using Property 10.9.
5 step solution
Problem 59
Perform the following calculations and express answers to the nearest hundredth. $$ \frac{\ln 2}{0.03} $$
4 step solution
Problem 59
Given that \(\log _{2} 5=2.3219\) and \(\log _{2} 7=2.8074\), evaluate each expression by using Properties \(10.5-10.7\) \(\log _{2} 80\)
4 step solution
Problem 59
Find the intervals on which the given function is increasing and the intervals on which it is decreasing. $$ f(x)=x^{2}+1 $$
5 step solution
Problem 59
Graph \(f(x)=e^{x}\). Where should the graphs of \(f(x)=\) \(e^{x-4}, f(x)=e^{x-6}\), and \(f(x)=e^{x+5}\) be located? Graph all three functions on the same set of axes with \(f(x)=e^{x}\).
5 step solution
Problem 60
Perform the following calculations and express answers to the nearest hundredth. $$ \frac{\log 2}{5 \log 1.02} $$
5 step solution
Problem 60
Given that \(\log _{8} 5=0.7740\) and \(\log _{8} 11=1.1531\), evaluate each expression using Properties \(10.5-10.7\) \(\log _{8} 55\)
4 step solution
Problem 60
Find the intervals on which the given function is increasing and the intervals on which it is decreasing. $$ f(x)=x^{3} $$
5 step solution
Problem 60
Graph \(f(x)=e^{x}\). Now predict the graphs for \(f(x)=\) \(-e^{x}, f(x)=e^{-x}\), and \(f(x)=-e^{-x}\). Graph all three functions on the same set of axes with \(f(x)=e^{x}\).
5 step solution
Problem 61
Explain how you would solve the equation \(2^{x}=64\) and also how you would solve the equation \(2^{x}=53\).
7 step solution
Problem 61
Perform the following calculations and express answers to the nearest hundredth. $$ \frac{\log 5}{3 \log 1.07} $$
5 step solution
Problem 61
Given that \(\log _{8} 5=0.7740\) and \(\log _{8} 11=1.1531\), evaluate each expression using Properties \(10.5-10.7\) \(\log _{8}\left(\frac{5}{11}\right)\)
4 step solution
Problem 61
Find the intervals on which the given function is increasing and the intervals on which it is decreasing. $$ f(x)=-3 x+1 $$
5 step solution
Problem 61
How do you think the graphs of \(f(x)=e^{x}, f(x)=e^{2 x}\), and \(f(x)=2 e^{x}\) will compare? Graph them on the same set of axes to see if you were correct.
4 step solution
Problem 62
How do logarithms with a base of 9 compare to logarithms with a base of 3 ? Explain how you reached this conclusion.
4 step solution
Problem 62
Given that \(\log _{8} 5=0.7740\) and \(\log _{8} 11=1.1531\), evaluate each expression using Properties \(10.5-10.7\) \(\log _{8} 25\)
4 step solution
Problem 62
Find the intervals on which the given function is increasing and the intervals on which it is decreasing. $$ f(x)=(x-3)^{2}+1 $$
5 step solution
Problem 62
Find an approximate solution, to the nearest hundredth, for each of the following equations by graphing the appropriate function and finding the \(x\) intercept. (a) \(e^{x}=7\) (b) \(e^{x}=21\) (c) \(e^{x}=53\) (d) \(2 e^{x}=60\) (e) \(e^{x+1}=150\) (f) \(e^{x-2}=300\)
5 step solution
Problem 63
Given that \(\log _{8} 5=0.7740\) and \(\log _{8} 11=1.1531\), evaluate each expression using Properties \(10.5-10.7\) \(\log _{8} \sqrt{11}\)
5 step solution
Problem 63
Find the intervals on which the given function is increasing and the intervals on which it is decreasing. $$ f(x)=-(x+2)^{2}-1 $$
4 step solution
Problem 64
Graph \(f(x)=x, f(x)=e^{x}\), and \(f(x)=\ln x\) on the same set of axes.
6 step solution
Problem 64
Given that \(\log _{8} 5=0.7740\) and \(\log _{8} 11=1.1531\), evaluate each expression using Properties \(10.5-10.7\) \(\log _{8}(5)^{2 / 3}\)
4 step solution
Problem 64
Find the intervals on which the given function is increasing and the intervals on which it is decreasing. $$ f(x)=x^{2}-2 x+6 $$
4 step solution
Problem 64
How long will it take \(\$ 500\) to be worth \(\$ 1500\) if it is invested at \(7.5 \%\) interest compounded semiannually?
8 step solution
Problem 65
Solve the equation \(\frac{5^{x}-5^{-x}}{2}=3\). Express your answer to the nearest hundredth. \(\\{1.13\\}\)
12 step solution
Problem 65
Graph \(f(x)=x, f(x)=10^{x}\), and \(f(x)=\log x\) on the same set of axes.
5 step solution
Problem 65
Given that \(\log _{8} 5=0.7740\) and \(\log _{8} 11=1.1531\), evaluate each expression using Properties \(10.5-10.7\) \(\log _{8} 88\)
5 step solution
Problem 65
Find the intervals on which the given function is increasing and the intervals on which it is decreasing. $$ f(x)=-2 x^{2}-16 x-35 $$
4 step solution
Problem 65
How long will it take \(\$ 5000\) to triple if it is invested at \(6.75 \%\) interest compounded quarterly?
5 step solution
Problem 66
$$ \text { Solve the equation } y=\frac{10^{x}+10^{-x}}{2} \text { for } x \text { in terms of } y \text {. } $$
4 step solution
Problem 66
Graph \(f(x)=\ln x\). How should the graphs of \(f(x)=2\) \(\ln x, f(x)=4 \ln x\), and \(f(x)=6 \ln x\) compare to the graph of \(f(x)=\ln x\) ? Graph the three functions on the same set of axes with \(f(x)=\ln x\).
5 step solution
Problem 66
Given that \(\log _{8} 5=0.7740\) and \(\log _{8} 11=1.1531\), evaluate each expression using Properties \(10.5-10.7\) \(\log _{8} 320\)
5 step solution
Problem 66
Find the intervals on which the given function is increasing and the intervals on which it is decreasing. $$ f(x)=x^{2}+3 x-1 $$
4 step solution
Problem 67
$$ \text { Solve the equation } y=\frac{e^{x}-e^{-x}}{2} \text { for } x \text { in terms of } y \text {. } $$
4 step solution
Problem 67
Graph \(f(x)=\log x\). Now predict the graphs for \(f(x)=\) \(2+\log x, f(x)=-2+\log x\), and \(f(x)=-6+\log x\). Graph the three functions on the same set of axes with \(f(x)=\log x\).
5 step solution
Problem 67
Given that \(\log _{8} 5=0.7740\) and \(\log _{8} 11=1.1531\), evaluate each expression using Properties \(10.5-10.7\) \(\log _{8}\left(\frac{25}{11}\right)\)
3 step solution
Problem 67
Does the function \(f(x)=4\) have an inverse? Explain your answer.
4 step solution
Problem 68
Graph \(\ln x\). Now predict the graphs for \(f(x)=\ln (x-2)\), \(f(x)=\ln (x-6)\), and \(f(x)=\ln (x+4)\). Graph the three functions on the same set of axes with \(f(x)=\ln x\).
5 step solution
Problem 68
Given that \(\log _{8} 5=0.7740\) and \(\log _{8} 11=1.1531\), evaluate each expression using Properties \(10.5-10.7\) \(\log _{8}\left(\frac{121}{25}\right)\)
6 step solution
Problem 69
Graph \(f(x)=x, f(x)=2^{x}\), and \(f(x)=\log _{2} x\) on the same set of axes.
6 step solution
Problem 69
For each of the following, (a) predict the general shape and location of the graph, and (b) use your graphing calculator to graph the function to check your prediction. (a) \(f(x)=\log x+\ln x\) (b) \(f(x)=\log x-\ln x\) (c) \(f(x)=\ln x-\log x\) (d) \(f(x)=\ln x^{2}\)
9 step solution
Problem 69
Express each of the following as the sum or difference of simpler logarithmic quantities. Assume that all variables represent positive real numbers. For example, $$ \begin{aligned} \log _{b} \frac{x^{3}}{y^{2}} &=\log _{b} x^{3}-\log _{b} y^{2} \\ &=3 \log _{b} x-2 \log _{b} y \end{aligned} $$ $$ \log _{b} x y z $$
4 step solution
Problem 69
Are the functions \(f(x)=x^{4}\) and \(g(x)=\sqrt[4]{x}\) inverses of each other? Explain your answer.
4 step solution
Problem 70
Graph \(f(x)=x, f(x)=(0.5)^{x}\), and \(f(x)=\log _{0.5} x\) on the same set of axes.
6 step solution
Problem 70
Express each of the following as the sum or difference of simpler logarithmic quantities. Assume that all variables represent positive real numbers. For example, $$ \begin{aligned} \log _{b} \frac{x^{3}}{y^{2}} &=\log _{b} x^{3}-\log _{b} y^{2} \\ &=3 \log _{b} x-2 \log _{b} y \end{aligned} $$ $$ \log _{h} 5 x $$
4 step solution
Problem 71
Graph \(f(x)=\log _{2} x\). Now predict the graphs for \(f(x)=\) \(\log _{3} x, f(x)=\log _{4} x\), and \(f(x)=\log _{8} x\). Graph these three functions on the same set of axes with $$ f(x)=\log _{2} x \text {. } $$
5 step solution
Problem 71
Express each of the following as the sum or difference of simpler logarithmic quantities. Assume that all variables represent positive real numbers. For example, $$ \begin{aligned} \log _{b} \frac{x^{3}}{y^{2}} &=\log _{b} x^{3}-\log _{b} y^{2} \\ &=3 \log _{b} x-2 \log _{b} y \end{aligned} $$ $$ \log _{b}\left(\frac{y}{z}\right) $$
2 step solution
Problem 71
The function notation and the operation of composition can be used to find inverses as follows: To find the inverse of \(f(x)=5 x+3\), we know that \(f\left(f^{-1}(x)\right)\) must produce \(x\). Therefore $$ \begin{aligned} f\left(f^{-1}(x)\right)=5\left[f^{-1}(x)\right]+3 &=x \\ 5\left[f^{-1}(x)\right] &=x-3 \\ f^{-1}(x) &=\frac{x-3}{5} \end{aligned} $$
4 step solution
Problem 72
Graph \(f(x)=\log _{5} x\). Now predict the graphs for \(f(x)=\) \(2 \log _{5} x, f(x)=-4 \log _{5} x\), and \(f(x)=\log _{5}(x+4)\). Graph these three functions on the same set of axes with \(f(x)=\log _{5} x\).
6 step solution
Problem 72
Express each of the following as the sum or difference of simpler logarithmic quantities. Assume that all variables represent positive real numbers. For example, $$ \begin{aligned} \log _{b} \frac{x^{3}}{y^{2}} &=\log _{b} x^{3}-\log _{b} y^{2} \\ &=3 \log _{b} x-2 \log _{b} y \end{aligned} $$ $$ \log _{b}\left(\frac{x^{2}}{y}\right) $$
3 step solution