Chapter 4

Algebra and Trigonometry · 519 exercises

Problem 83

Solve each logarithmic equation. Be sure to reject any value of \(x\) that is not in the domain of the original logarithmic expressions. Give the exact answer. Then, where necessary, use a calculator to obtain a decimal approximation, correct to two decimal places, for the solution. $$ \log (x+4)-\log 2=\log (5 x+1) $$

5 step solution

Problem 84

Begin by graphing \(y=|x| .\) Then use this graph to obtain the graph of \(y=|x-2|+1 . \)

4 step solution

Problem 84

Let \(\log _{b} 2=A\) and \(\log _{b} 3=C .\)Write each expression in terms of \(A\) and \(C\). $$ \log _{b} 6 $$

3 step solution

Problem 84

Solve each logarithmic equation. Be sure to reject any value of \(x\) that is not in the domain of the original logarithmic expressions. Give the exact answer. Then, where necessary, use a calculator to obtain a decimal approximation, correct to two decimal places, for the solution. $$ \log (x+7)-\log 3=\log (7 x+1) $$

4 step solution

Problem 84

In Exercises 81–100, evaluate or simplify each expression without using a calculator. $$ \log 10^{8} $$

2 step solution

Problem 84

determine whether each statement makes sense or does not make sense, and explain your reasoning. I'm using a photocopier to reduce an image over and over by \(50 \%,\) so the exponential function \(f(x)=\left(\frac{1}{2}\right)^{x}\) models the new image size, where \(x\) is the number of reductions.

3 step solution

Problem 85

Write an equation in point-slope form and slope-intercept form of the line passing through \((1,-4)\) and parallel to the line whose equation is \(3 x-y+5=0 .\)

3 step solution

Problem 85

Let \(\log _{b} 2=A\) and \(\log _{b} 3=C .\)Write each expression in terms of \(A\) and \(C\). $$ \log _{b} 8 $$

3 step solution

Problem 85

Solve each logarithmic equation. Be sure to reject any value of \(x\) that is not in the domain of the original logarithmic expressions. Give the exact answer. Then, where necessary, use a calculator to obtain a decimal approximation, correct to two decimal places, for the solution. $$ 2 \log x-\log 7=\log 112 $$

3 step solution

Problem 85

In Exercises 81–100, evaluate or simplify each expression without using a calculator. $$ 10^{\log 33} $$

2 step solution

Problem 85

determine whether each statement makes sense or does not make sense, and explain your reasoning. Taxing thoughts: I'm looking at data that show the number of pages in the publication that explains the U.S. tax code for selected years from 1945 thorugh 2013 . A linear function appears to be a better choice than an exponential function for modeling the number of pages in the tax code during this period.

3 step solution

Problem 86

Exercises \(86-88\) will help you prepare for the material covered in the first section of the next chapter. $$ \text { Solve: } \quad \frac{5 \pi}{4}=2 \pi x $$

4 step solution

Problem 86

Let \(\log _{b} 2=A\) and \(\log _{b} 3=C .\)Write each expression in terms of \(A\) and \(C\). $$ \log _{b} 81 $$

4 step solution

Problem 86

Solve each logarithmic equation. Be sure to reject any value of \(x\) that is not in the domain of the original logarithmic expressions. Give the exact answer. Then, where necessary, use a calculator to obtain a decimal approximation, correct to two decimal places, for the solution. $$ \log (x-2)+\log 5=\log 100 $$

3 step solution

Problem 86

In Exercises 81–100, evaluate or simplify each expression without using a calculator. $$ 10^{\log 53} $$

2 step solution

Problem 86

determine whether each statement makes sense or does not make sense, and explain your reasoning. I use the natural base \(e\) when determining how much money I'd have in a bank account that earns compound interest subject to continuous compounding.

3 step solution

Problem 87

Exercises \(86-88\) will help you prepare for the material covered in the first section of the next chapter. $$ \text { Simplify: } \frac{17 \pi}{6}-2 \pi $$

3 step solution

Problem 87

Let \(\log _{b} 2=A\) and \(\log _{b} 3=C .\)Write each expression in terms of \(A\) and \(C\). $$ \log _{b} \sqrt{\frac{2}{27}} $$

3 step solution

Problem 87

Solve each logarithmic equation. Be sure to reject any value of \(x\) that is not in the domain of the original logarithmic expressions. Give the exact answer. Then, where necessary, use a calculator to obtain a decimal approximation, correct to two decimal places, for the solution. $$ \log x+\log (x+3)=\log 10 $$

5 step solution

Problem 87

In Exercises 81–100, evaluate or simplify each expression without using a calculator. $$ \ln 1 $$

2 step solution

Problem 88

Exercises \(86-88\) will help you prepare for the material covered in the first section of the next chapter. $$ \text { Simplify: }-\frac{\pi}{12}+2 \pi $$

3 step solution

Problem 88

Let \(\log _{b} 2=A\) and \(\log _{b} 3=C .\)Write each expression in terms of \(A\) and \(C\). $$ \log _{b} \sqrt{\frac{3}{16}} $$

4 step solution

Problem 88

Solve each logarithmic equation. Be sure to reject any value of \(x\) that is not in the domain of the original logarithmic expressions. Give the exact answer. Then, where necessary, use a calculator to obtain a decimal approximation, correct to two decimal places, for the solution. $$ \log (x+3)+\log (x-2)=\log 14 $$

4 step solution

Problem 88

In Exercises 81–100, evaluate or simplify each expression without using a calculator. $$ \ln e $$

2 step solution

Problem 89

Solve each logarithmic equation. Be sure to reject any value of \(x\) that is not in the domain of the original logarithmic expressions. Give the exact answer. Then, where necessary, use a calculator to obtain a decimal approximation, correct to two decimal places, for the solution. $$ \ln (x-4)+\ln (x+1)=\ln (x-8) $$

5 step solution

Problem 89

In Exercises 81–100, evaluate or simplify each expression without using a calculator. $$ \ln e^{20} $$

2 step solution

Problem 90

Solve each logarithmic equation. Be sure to reject any value of \(x\) that is not in the domain of the original logarithmic expressions. Give the exact answer. Then, where necessary, use a calculator to obtain a decimal approximation, correct to two decimal places, for the solution. $$ \log _{2}(x-1)-\log _{2}(x+3)=\log _{2}\left(\frac{1}{x}\right) $$

5 step solution

Problem 90

In Exercises 81–100, evaluate or simplify each expression without using a calculator. $$ \ln e^{7} $$

4 step solution

Problem 90

determine whether each statement is true or false. If the statement is false, make the necessary change(s) to produce a true statement. The functions \(f(x)=\left(\frac{1}{3}\right)^{x}\) and \(g(x)=3^{-x}\) have the same graph.

3 step solution

Problem 91

Determine whether each equation is true or false. Where possible, show work to support your conclusion. If the statement is false, make the necessary change(s) to produce a true statement. $$ \log _{4}\left(2 x^{3}\right)=3 \log _{4}(2 x) $$

3 step solution

Problem 91

Solve each logarithmic equation. Be sure to reject any value of \(x\) that is not in the domain of the original logarithmic expressions. Give the exact answer. Then, where necessary, use a calculator to obtain a decimal approximation, correct to two decimal places, for the solution. $$ \ln (x-2)-\ln (x+3)=\ln (x-1)-\ln (x+7) $$

4 step solution

Problem 91

In Exercises 81–100, evaluate or simplify each expression without using a calculator. $$ \ln \frac{1}{e^{6}} $$

3 step solution

Problem 92

In Exercises 81–100, evaluate or simplify each expression without using a calculator. $$ \ln \frac{1}{e^{7}} $$

3 step solution

Problem 92

Graph \(f(x)=2^{x}\) and its inverse function in the same rectangular coordinate system.

5 step solution

Problem 93

Solve each equation. $$ 5^{2 x} \cdot 5^{4 x}=125 $$

5 step solution

Problem 93

In Exercises 81–100, evaluate or simplify each expression without using a calculator. $$ e^{\ln 125} $$

2 step solution

Problem 93

The hyperbolic cosine and hyperbolic sine functions are defined by $$ \cosh x=\frac{e^{x}+e^{-x}}{2} \quad \text { and } \quad \sinh x=\frac{e^{x}-e^{-x}}{2} $$ a. Show that \(\cosh x\) is an even function. b. Show that \(\sinh x\) is an odd function. c. Prove that \((\cosh x)^{2}-(\sinh x)^{2}=1\)

3 step solution

Problem 94

Solve each equation. $$ 3^{x+2} \cdot 3^{x}=81 $$

4 step solution

Problem 94

Determine whether each equation is true or false. Where possible, show work to support your conclusion. If the statement is false, make the necessary change(s) to produce a true statement. $$ \ln (x+1)=\ln x+\ln 1 $$

4 step solution

Problem 94

In Exercises 81–100, evaluate or simplify each expression without using a calculator. $$ e^{\ln 300} $$

2 step solution

Problem 94

Solve for \(y: 7 x+3 y=18 .\) (Section \(1.3,\) Example 7 )

3 step solution

Problem 95

Solve each equation. $$ 2|\ln x|-6=0 $$

3 step solution

Problem 95

Determine whether each equation is true or false. Where possible, show work to support your conclusion. If the statement is false, make the necessary change(s) to produce a true statement. $$ \ln (5 x)+\ln 1=\ln (5 x) $$

4 step solution

Problem 95

In Exercises 81–100, evaluate or simplify each expression without using a calculator. $$ \ln e^{9 x} $$

2 step solution

Problem 95

Find all zeros of \(f(x)=x^{3}+5 x^{2}-8 x+2 .\) (Section 3.4 Example 4 )

4 step solution

Problem 96

Solve each equation. $$ 3|\log x|-6=0 $$

3 step solution

Problem 96

In Exercises 81–100, evaluate or simplify each expression without using a calculator. $$ \ln e^{13 x} $$

3 step solution

Problem 96

Solve and graph the solution set on a number line: \(2 x^{2}+5 x<12\). (Section \(3.6,\) Example 1 )

5 step solution

Problem 97

Determine whether each equation is true or false. Where possible, show work to support your conclusion. If the statement is false, make the necessary change(s) to produce a true statement. $$ \log (x+3)-\log (2 x)=\frac{\log (x+3)}{\log (2 x)} $$

3 step solution

Problem 97

In Exercises 81–100, evaluate or simplify each expression without using a calculator. $$ e^{\ln 5 x^{2}} $$

2 step solution

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