Chapter 4
Precalculus : Building Concepts and Connections · 431 exercises
Problem 48
In Exercises \(47-52,\) let \(b=\log\) k. Write each expression in terms of b. Assume \(k>0\). $$\log 100 k$$
3 step solution
Problem 49
Use the change-of-base formula to evaluate each logarithm using a calculator. Round answers to four decimal places. $$. \log _{7} 150$$
3 step solution
Problem 49
Explain why the function \(f(t)=e^{(1 / 2) t}\) cannot model exponential decay.
5 step solution
Problem 49
Find the inverse of the given function. Then graph the given function and its inverse on the same set of axes. $$f(x)=-4 x^{5}+9$$
4 step solution
Problem 49
Solve the logarithmic equation and eliminate any extraneous solutions. If there are no solutions, so state. $$\ln (2 x)=1+\ln (x+3)$$
5 step solution
Problem 49
In Exercises \(47-52,\) let \(b=\log\) k. Write each expression in terms of b. Assume \(k>0\). $$\log k^{3}$$
2 step solution
Problem 50
Find the inverse of the given function. Then graph the given function and its inverse on the same set of axes. $$g(x)=2 x^{5}-6$$
2 step solution
Problem 50
Solve the logarithmic equation and eliminate any extraneous solutions. If there are no solutions, so state. $$\log _{3} x=2+\log _{3}(x-2)$$
5 step solution
Problem 50
In Exercises \(47-52,\) let \(b=\log\) k. Write each expression in terms of b. Assume \(k>0\). $$\log k^{4}$$
2 step solution
Problem 50
Use the change-of-base formula to evaluate each logarithm using a calculator. Round answers to four decimal places. $$\log _{7} 230$$
3 step solution
Problem 51
Find the inverse of the given function. Then graph the given function and its inverse on the same set of axes. $$f(x)=\frac{1}{x}$$
3 step solution
Problem 51
Solve the logarithmic equation and eliminate any extraneous solutions. If there are no solutions, so state. $$\log (3 x+1)-\log \left(x^{2}+1\right)=0$$
4 step solution
Problem 51
In Exercises \(47-52,\) let \(b=\log\) k. Write each expression in terms of b. Assume \(k>0\). $$\log \frac{1}{k}$$
4 step solution
Problem 51
Use the definition of a logarithm to solve for \(x\). $$\log _{2} x=3$$
3 step solution
Problem 52
Find the inverse of the given function. Then graph the given function and its inverse on the same set of axes. $$g(x)=\frac{-1}{2 x}$$
3 step solution
Problem 52
Solve the logarithmic equation and eliminate any extraneous solutions. If there are no solutions, so state. $$\log (x+5)-\log \left(4 x^{2}+5\right)=0$$
3 step solution
Problem 52
In Exercises \(47-52,\) let \(b=\log\) k. Write each expression in terms of b. Assume \(k>0\). $$\log \frac{1}{k^{3}}$$
3 step solution
Problem 52
Use the definition of a logarithm to solve for \(x\). $$ \log _{5} \sqrt{5}=x$$
3 step solution
Problem 53
Find the inverse of the given function. Then graph the given function and its inverse on the same set of axes. $$g(x)=(x-1)^{2}, x \geq 1$$
3 step solution
Problem 53
Solve the logarithmic equation and eliminate any extraneous solutions. If there are no solutions, so state. $$\log (2 x+5)+\log (x+1)=1$$
4 step solution
Problem 53
In Exercises \(53-64,\) simplify each expression. Assume that each variable expression is defined for appropriate values of \(x .\) Do not use a calculator. $$\log 10^{\sqrt{2}}$$
2 step solution
Problem 53
Use a graphing utility to solve each equation for \(x.\) $$5=3^{x}$$
3 step solution
Problem 53
Use the definition of a logarithm to solve for \(x\). $$\log _{3} x=\frac{1}{3}$$
2 step solution
Problem 54
Find the inverse of the given function. Then graph the given function and its inverse on the same set of axes. $$g(x)=(x+2)^{2}, x \geq-2$$
4 step solution
Problem 54
Solve the logarithmic equation and eliminate any extraneous solutions. If there are no solutions, so state. $$\log (3 x+1)+\log (x+1)=1$$
4 step solution
Problem 54
In Exercises \(53-64,\) simplify each expression. Assume that each variable expression is defined for appropriate values of \(x .\) Do not use a calculator. $$\log 10^{2 x}$$
3 step solution
Problem 54
Use a graphing utility to solve each equation for \(x.\) $$7=4^{x}$$
3 step solution
Problem 54
Use the definition of a logarithm to solve for \(x\). $$\log _{6} x=-2$$
4 step solution
Problem 55
Find the inverse of the given function. Then graph the given function and its inverse on the same set of axes. $$f(x)=\sqrt{x+3}, x \geq-3$$
3 step solution
Problem 55
Solve the logarithmic equation and eliminate any extraneous solutions. If there are no solutions, so state. $$\log _{2}(x+5)=\log _{2}(x)+\log _{2}(x-3)$$
6 step solution
Problem 55
In Exercises \(53-64,\) simplify each expression. Assume that each variable expression is defined for appropriate values of \(x .\) Do not use a calculator. $$\ln e^{\sqrt{3}}$$
2 step solution
Problem 55
Use a graphing utility to solve each equation for \(x.\) $$10=2^{-x}$$
3 step solution
Problem 56
Find the inverse of the given function. Then graph the given function and its inverse on the same set of axes. $$f(x)=\sqrt{x-4}, x \geq 4$$
2 step solution
Problem 56
Solve the logarithmic equation and eliminate any extraneous solutions. If there are no solutions, so state. $$\ln 2 x-\ln \left(x^{2}+1\right)=\ln 1$$
4 step solution
Problem 56
In Exercises \(53-64,\) simplify each expression. Assume that each variable expression is defined for appropriate values of \(x .\) Do not use a calculator. $$\ln e^{(x+1)}$$
2 step solution
Problem 56
Use a graphing utility to solve each equation for \(x.\) $$20=100(5)^{-x}$$
3 step solution
Problem 56
Use the definition of a logarithm to solve for \(x\). $$\log _{x} 9=\frac{1}{2}$$
4 step solution
Problem 57
Find the inverse of the given function. Then graph the given function and its inverse on the same set of axes. $$f(x)=\frac{2 x}{x-1}$$
2 step solution
Problem 57
Solve the logarithmic equation and eliminate any extraneous solutions. If there are no solutions, so state. $$2 \ln x+\ln (x-1)=3.1$$
5 step solution
Problem 57
In Exercises \(53-64,\) simplify each expression. Assume that each variable expression is defined for appropriate values of \(x .\) Do not use a calculator. $$10^{\log (5 x)}$$
4 step solution
Problem 57
Use a graphing utility to solve each equation for \(x.\) $$100=50 e^{0.06 x}$$
4 step solution
Problem 57
Find the domain of each function. Use your answer to help you graph the function, and label all asymptotes. $$f(x)=2 \log x$$
3 step solution
Problem 58
Find the inverse of the given function. Then graph the given function and its inverse on the same set of axes. $$f(x)=\frac{x+3}{x}$$
4 step solution
Problem 58
Solve the logarithmic equation and eliminate any extraneous solutions. If there are no solutions, so state. $$-\ln x-\ln (x+2)=2.5$$
4 step solution
Problem 58
In Exercises \(53-64,\) simplify each expression. Assume that each variable expression is defined for appropriate values of \(x .\) Do not use a calculator. $$e^{\ln \left(5 x^{2}-1\right)}$$
2 step solution
Problem 58
Use a graphing utility to solve each equation for \(x.\) $$25=50 e^{-0.05 x}$$
3 step solution
Problem 58
Find the domain of each function. Use your answer to help you graph the function, and label all asymptotes. $$f(x)=4 \ln x$$
3 step solution
Problem 59
Solve the logarithmic equation and eliminate any extraneous solutions. If there are no solutions, so state. $$\log |x-2|+\log |x|=1.2$$
5 step solution
Problem 59
In Exercises \(53-64,\) simplify each expression. Assume that each variable expression is defined for appropriate values of \(x .\) Do not use a calculator. $$10^{\log (3 x+1)}$$
2 step solution
Problem 59
Consider the function \(f(x)=x e^{-x}.\) (a) Use a graphing utility to graph this function, with \(x\) ranging from -5 to \(5 .\) You may need to scroll through the table of values to set an appropriate scale for the vertical axis. (b) What are the domain and range of \(f ?\) (c) What are the \(x\) - and \(y\) -intercepts, if any, of the graph of this function? (d) Describe the behavior of the function as \(x\) approaches \(\pm \infty.\)
4 step solution