Chapter 4
College Algebra Essentials · 476 exercises
Problem 14
Use properties of logarithms to expand logarithmic expression as much as possible. Where possible, evaluate logarithmic expressions without using a calculator. \(\ln \left(\frac{e^{4}}{8}\right)\)
3 step solution
Problem 15
An artifact originally had 16 grams of carbon- 14 present. The decay model \(A=16 e^{-0.0001211}\) describes the amount of carbon-I4 present after t years. Use this model to solve Exercises \(15-16 .\) How many grams of carbon-14 will be present in 5715 years?
3 step solution
Problem 15
Solve each exponential equation by expressing each side as a power of the same base and then equating exponents. $$6^{\frac{x-3}{4}}=\sqrt{6}$$
3 step solution
Problem 15
Write each equation in its equivalent logarithmic form. $$13^{2}=x$$
2 step solution
Problem 15
Graph each function by making a table of coordinates. If applicable, use a graphing utility to confirm your hand-drawn graph. $$h(x)=\left(\frac{1}{2}\right)^{x}$$
3 step solution
Problem 15
Use properties of logarithms to expand logarithmic expression as much as possible. Where possible, evaluate logarithmic expressions without using a calculator. \(\log _{b} x^{3}\)
6 step solution
Problem 16
An artifact originally had 16 grams of carbon- 14 present. The decay model \(A=16 e^{-0.0001211}\) describes the amount of carbon-I4 present after t years. Use this model to solve Exercises \(15-16 .\) How many grams of carbon-14 will be present in \(11,430\) years?
4 step solution
Problem 16
Solve each exponential equation by expressing each side as a power of the same base and then equating exponents. $$7^{\frac{x-2}{6}}=\sqrt{7}$$
3 step solution
Problem 16
Write each equation in its equivalent logarithmic form. $$15^{2}=x$$
2 step solution
Problem 16
Graph each function by making a table of coordinates. If applicable, use a graphing utility to confirm your hand-drawn graph. $$h(x)=\left(\frac{1}{3}\right)^{x}$$
4 step solution
Problem 16
Use properties of logarithms to expand logarithmic expression as much as possible. Where possible, evaluate logarithmic expressions without using a calculator. \(\log _{b} x^{7}\)
2 step solution
Problem 17
The half-life of the radioactive element krypton-91 is 10 seconds. If 16 grams of krypton-91 are initially present, how many grams are present after 10 seconds? 20 seconds? 30 seconds? 40 seconds? 50 seconds?
3 step solution
Problem 17
Solve each exponential equation by expressing each side as a power of the same base and then equating exponents. $$4^{x}=\frac{1}{\sqrt{2}}$$
3 step solution
Problem 17
Write each equation in its equivalent logarithmic form. $$b^{3}=1000$$
2 step solution
Problem 17
Graph each function by making a table of coordinates. If applicable, use a graphing utility to confirm your hand-drawn graph. $$f(x)=(0.6)^{x}$$
3 step solution
Problem 17
Use properties of logarithms to expand logarithmic expression as much as possible. Where possible, evaluate logarithmic expressions without using a calculator. \(\log N^{-6}\)
2 step solution
Problem 18
The half-life of the radioactive element plutonium-239 is \(25,000\) years. If 16 grams of plutonium- 239 are initially present, how many grams are present after \(25,000\) years? \(50,000\) years? \(75,000\) years? \(100,000\) years? \(125,000\) years?
6 step solution
Problem 18
Solve each exponential equation by expressing each side as a power of the same base and then equating exponents. $$9^{x}=\frac{1}{\sqrt[3]{3}}$$
3 step solution
Problem 18
Write each equation in its equivalent logarithmic form. $$b^{3}=343$$
2 step solution
Problem 18
Graph each function by making a table of coordinates. If applicable, use a graphing utility to confirm your hand-drawn graph. $$f(x)=(0.8)^{x}$$
3 step solution
Problem 18
Use properties of logarithms to expand logarithmic expression as much as possible. Where possible, evaluate logarithmic expressions without using a calculator. \(\log M^{-8}\)
3 step solution
Problem 19
Solve each exponential equation by expressing each side as a power of the same base and then equating exponents. $$8^{x+3}=16^{x-1}$$
4 step solution
Problem 19
Write each equation in its equivalent logarithmic form. $$7^{y}=200$$
4 step solution
Problem 19
Use properties of logarithms to expand logarithmic expression as much as possible. Where possible, evaluate logarithmic expressions without using a calculator. \(\ln \sqrt[5]{x}\)
4 step solution
Problem 20
Use the exponential decay model for carbon- \(14, A=A_{0} e^{-0.000121 t}\) to solve Exercises \(19-20\) Skeletons were found at a construction site in San Francisco in \(1989 .\) The skeletons contained \(88 \%\) of the expected amount of carbon-14 found in a living person. In \(1989,\) how old were the skeletons?
4 step solution
Problem 20
Solve each exponential equation by expressing each side as a power of the same base and then equating exponents. $$8^{1-x}=4^{x+2}$$
3 step solution
Problem 20
Write each equation in its equivalent logarithmic form. $$8^{y}=300$$
2 step solution
Problem 20
Use properties of logarithms to expand logarithmic expression as much as possible. Where possible, evaluate logarithmic expressions without using a calculator. \(\ln \sqrt[7]{x}\)
3 step solution
Problem 21
Solve each exponential equation by expressing each side as a power of the same base and then equating exponents. $$e^{x+1}=\frac{1}{e}$$
3 step solution
Problem 21
Evaluate each expression without using a calculator. $$\log _{4} 16$$
3 step solution
Problem 21
Use properties of logarithms to expand logarithmic expression as much as possible. Where possible, evaluate logarithmic expressions without using a calculator. \(\log _{b}\left(x^{2} y\right)\)
3 step solution
Problem 22
Solve each exponential equation by expressing each side as a power of the same base and then equating exponents. $$e^{x+4}=\frac{1}{e^{2 x}}$$
3 step solution
Problem 22
Evaluate each expression without using a calculator. $$\log _{7} 49$$
2 step solution
Problem 22
Use properties of logarithms to expand logarithmic expression as much as possible. Where possible, evaluate logarithmic expressions without using a calculator. \(\log _{b}\left(x y^{3}\right)\)
3 step solution
Problem 23
Solve each exponential equation. Express the solution set in terms of natural logarithms or common logarithms. Then use a calculator to obtain a decimal approximation, correct to two decimal places, for the solution. $$10^{x}=3.91$$
3 step solution
Problem 23
Evaluate each expression without using a calculator. $$\log _{2} 64$$
3 step solution
Problem 23
Use properties of logarithms to expand logarithmic expression as much as possible. Where possible, evaluate logarithmic expressions without using a calculator. \(\log _{4}\left(\frac{\sqrt{x}}{64}\right)\)
4 step solution
Problem 24
Solve each exponential equation. Express the solution set in terms of natural logarithms or common logarithms. Then use a calculator to obtain a decimal approximation, correct to two decimal places, for the solution. $$10^{x}=8.07$$
3 step solution
Problem 24
Evaluate each expression without using a calculator. $$\log _{3} 27$$
3 step solution
Problem 24
Use properties of logarithms to expand logarithmic expression as much as possible. Where possible, evaluate logarithmic expressions without using a calculator. \(\log _{5}\left(\frac{\sqrt{x}}{25}\right)\)
4 step solution
Problem 25
Solve each exponential equation. Express the solution set in terms of natural logarithms or common logarithms. Then use a calculator to obtain a decimal approximation, correct to two decimal places, for the solution. $$e^{x}=5.7$$
3 step solution
Problem 25
Begin by graphing \(f(x)=2^{x}\). Then use transformations of this graph to graph the given function. Be sure to graph and give equations of the asymptotes. Use the graphs to determine each function's domain and range. If applicable, use a graphing utility to confirm your hand-drawn graphs. $$g(x)=2^{x+1}$$
5 step solution
Problem 25
Evaluate each expression without using a calculator. $$\log _{5} \frac{1}{5}$$
3 step solution
Problem 25
Use properties of logarithms to expand logarithmic expression as much as possible. Where possible, evaluate logarithmic expressions without using a calculator. \(\log _{6}\left(\frac{36}{\sqrt{x+1}}\right)\)
5 step solution
Problem 26
Solve each exponential equation. Express the solution set in terms of natural logarithms or common logarithms. Then use a calculator to obtain a decimal approximation, correct to two decimal places, for the solution. $$e^{x}=0.83$$
2 step solution
Problem 26
Begin by graphing \(f(x)=2^{x}\). Then use transformations of this graph to graph the given function. Be sure to graph and give equations of the asymptotes. Use the graphs to determine each function's domain and range. If applicable, use a graphing utility to confirm your hand-drawn graphs. $$g(x)=2^{x+2}$$
4 step solution
Problem 26
Evaluate each expression without using a calculator. $$\log _{6} \frac{1}{6}$$
3 step solution
Problem 26
Use properties of logarithms to expand logarithmic expression as much as possible. Where possible, evaluate logarithmic expressions without using a calculator. \(\log _{8}\left(\frac{64}{\sqrt{x+1}}\right)\)
4 step solution
Problem 27
Solve each exponential equation. Express the solution set in terms of natural logarithms or common logarithms. Then use a calculator to obtain a decimal approximation, correct to two decimal places, for the solution. $$5^{x}=17$$
3 step solution
Problem 27
Begin by graphing \(f(x)=2^{x}\). Then use transformations of this graph to graph the given function. Be sure to graph and give equations of the asymptotes. Use the graphs to determine each function's domain and range. If applicable, use a graphing utility to confirm your hand-drawn graphs. $$g(x)=2^{x}-1$$
4 step solution