Chapter 4

Algebra and Trigonometry Real Mathematics, Real People · 550 exercises

Problem 63

Write the logarithmic equation in exponential form. For example, the exponential form of \(\ln 5=1.6094\). . . is \(e^{1.6094 \cdots}=5.\) $$\ln e=1$$

2 step solution

Problem 63

Solve the exponential equation algebraically. Round your result to three decimal places. Use a graphing utility to verify your answer. $$7-2 e^{x}=1$$

5 step solution

Problem 63

(a) use a graphing utility to graph the function, (b) use the graph to find the open intervals on which the function is increasing and decreasing, and (c) approximate any relative maximum or minimum values. $$f(x)=x^{3} e^{x}$$

3 step solution

Problem 64

Use the properties of logarithms to expand the expression as a sum, difference, and/or constant multiple of logarithms. (Assume all variables are positive.)$$\log _{b} \frac{\sqrt{x} y^{4}}{z^{4}}$$.

3 step solution

Problem 64

Write the logarithmic equation in exponential form. For example, the exponential form of \(\ln 5=1.6094\). . . is \(e^{1.6094 \cdots}=5.\) $$\ln e^{3}=3$$

2 step solution

Problem 64

Solve the exponential equation algebraically. Round your result to three decimal places. Use a graphing utility to verify your answer. $$-14+3 e^{x}=11$$

4 step solution

Problem 64

(a) use a graphing utility to graph the function, (b) use the graph to find the open intervals on which the function is increasing and decreasing, and (c) approximate any relative maximum or minimum values. $$f(x)=x^{3} e^{-x+2}$$

3 step solution

Problem 65

(a) use a graphing utility to graph the two equations in the same viewing window and (b) use the table feature of the graphing utility to create a table of values for each equation. (c) What do the graphs and tables suggest? Verify your conclusion algebraically.$$\begin{array}{l}y_{1}=\ln \left[x^{2}(x-4)\right] \\\y_{2}=2 \ln x+\ln (x-4)\end{array}$$

4 step solution

Problem 65

Write the logarithmic equation in exponential form. For example, the exponential form of \(\ln 5=1.6094\). . . is \(e^{1.6094 \cdots}=5.\) $$\ln \sqrt{e}=\frac{1}{2}$$

2 step solution

Problem 65

Solve the exponential equation algebraically. Round your result to three decimal places. Use a graphing utility to verify your answer. $$5\left(2^{3-x}\right)-13=100$$

4 step solution

Problem 65

Complete the table to determine the balance \(A\) for \(\$ 2500\) invested at rate \(r\) for \(t\) years and compounded \(n\) times per year. $$\begin{array}{|c|c|c|c|c|c|c|} \hline n & 1 & 2 & 4 & 12 & 365 & \text { Continuous } \\ \hline A & & & & & & \\ \hline \end{array}$$ $$r=2 \%, t=10 \text { years }$$

8 step solution

Problem 66

(a) use a graphing utility to graph the two equations in the same viewing window and (b) use the table feature of the graphing utility to create a table of values for each equation. (c) What do the graphs and tables suggest? Verify your conclusion algebraically.$$\begin{array}{l}y_{1}=\ln 9 x^{3} \\\y_{2}=\ln 9+3 \ln x\end{array}$$

4 step solution

Problem 66

Write the logarithmic equation in exponential form. For example, the exponential form of \(\ln 5=1.6094\). . . is \(e^{1.6094 \cdots}=5.\) $$\ln \frac{1}{e^{2}}=-2$$

2 step solution

Problem 66

Solve the exponential equation algebraically. Round your result to three decimal places. Use a graphing utility to verify your answer. $$6\left(8^{-2-x}\right)+15=2601$$

6 step solution

Problem 66

Complete the table to determine the balance \(A\) for \(\$ 2500\) invested at rate \(r\) for \(t\) years and compounded \(n\) times per year. $$\begin{array}{|c|c|c|c|c|c|c|} \hline n & 1 & 2 & 4 & 12 & 365 & \text { Continuous } \\ \hline A & & & & & & \\ \hline \end{array}$$ $$r=6 \%, t=10 \text { years }$$

4 step solution

Problem 67

(a) use a graphing utility to graph the two equations in the same viewing window and (b) use the table feature of the graphing utility to create a table of values for each equation. (c) What do the graphs and tables suggest? Verify your conclusion algebraically.$$\begin{aligned}&y_{1}=\ln \left(\frac{x^{4}}{x-2}\right)\\\&y_{2}=4 \ln x-\ln (x-2)\end{aligned}$$.

4 step solution

Problem 67

Write the logarithmic equation in exponential form. For example, the exponential form of \(\ln 5=1.6094\). . . is \(e^{1.6094 \cdots}=5.\) $$\ln 9=2.1972 . . .$$

2 step solution

Problem 67

Solve the exponential equation algebraically. Round your result to three decimal places. Use a graphing utility to verify your answer. $$\left(1+\frac{0.10}{12}\right)^{12 t}=2$$

4 step solution

Problem 67

Complete the table to determine the balance \(A\) for \(\$ 2500\) invested at rate \(r\) for \(t\) years and compounded \(n\) times per year. $$\begin{array}{|c|c|c|c|c|c|c|} \hline n & 1 & 2 & 4 & 12 & 365 & \text { Continuous } \\ \hline A & & & & & & \\ \hline \end{array}$$ $$r=4 \%, t=20 \text { years }$$

3 step solution

Problem 68

(a) use a graphing utility to graph the two equations in the same viewing window and (b) use the table feature of the graphing utility to create a table of values for each equation. (c) What do the graphs and tables suggest? Verify your conclusion algebraically.$$\begin{array}{l}y_{1}=\ln \left(\frac{\sqrt{x}}{x+3}\right) \\\y_{2}=\frac{1}{2} \ln x-\ln (x+3)\end{array}$$.

4 step solution

Problem 68

Write the logarithmic equation in exponential form. For example, the exponential form of \(\ln 5=1.6094\). . . is \(e^{1.6094 \cdots}=5.\) $$\ln \sqrt[3]{e}=\frac{1}{3}$$

2 step solution

Problem 68

Solve the exponential equation algebraically. Round your result to three decimal places. Use a graphing utility to verify your answer. $$\left(16+\frac{0.878}{26}\right)^{3 t}=30$$

5 step solution

Problem 68

Complete the table to determine the balance \(A\) for \(\$ 2500\) invested at rate \(r\) for \(t\) years and compounded \(n\) times per year. $$\begin{array}{|c|c|c|c|c|c|c|} \hline n & 1 & 2 & 4 & 12 & 365 & \text { Continuous } \\ \hline A & & & & & & \\ \hline \end{array}$$ $$r=3 \%, t=40 \text { years }$$

3 step solution

Problem 69

Use the properties of logarithms to condense the expression.$$\ln x+\ln 4$$.

3 step solution

Problem 69

Write the exponential equation in logarithmic form. For example, the logarithmic form of \(e^{2}=7.3890 . . .\) is \(\ln 7.3890 . . .=2.\) $$e^{3}=20.0855 . . . $$

3 step solution

Problem 69

Solve the exponential equation algebraically. Round your result to three decimal places. Use a graphing utility to verify your answer. $$5000\left[\frac{(1+0.005)^{x}}{0.005}\right]=250,000$$

6 step solution

Problem 69

Complete the table to determine the balance \(A\) for \(\$ 12,000\) invested at rate \(r\) for \(t\) years, compounded continuously.. Complete the table to determine the balance \(A\) for \(\$ 12,000\) invested at rate \(r\) for \(t\) years, compounded continuously.. $$\begin{array}{|c|c|c|c|c|c|c|} \hline t & 1 & 10 & 20 & 30 & 40 & 50 \\ \hline A & & & & & & \\ \hline \end{array}$$ $$r=4 \%$$

8 step solution

Problem 70

Use the properties of logarithms to condense the expression.$$\ln y+\ln z$$.

3 step solution

Problem 70

Write the exponential equation in logarithmic form. For example, the logarithmic form of \(e^{2}=7.3890 . . .\) is \(\ln 7.3890 . . .=2.\) $$e^{0}=1$$

3 step solution

Problem 70

Solve the exponential equation algebraically. Round your result to three decimal places. Use a graphing utility to verify your answer. $$250\left[\frac{(1+0.01)^{x}}{0.01}\right]=150,000$$

5 step solution

Problem 70

Complete the table to determine the balance \(A\) for \(\$ 12,000\) invested at rate \(r\) for \(t\) years, compounded continuously.. $$\begin{array}{|c|c|c|c|c|c|c|} \hline t & 1 & 10 & 20 & 30 & 40 & 50 \\ \hline A & & & & & & \\ \hline \end{array}$$ $$r=6 \%$$

6 step solution

Problem 71

Use the properties of logarithms to condense the expression.$$\log _{4} z-\log _{4} y$$.

2 step solution

Problem 71

Write the exponential equation in logarithmic form. For example, the logarithmic form of \(e^{2}=7.3890 . . .\) is \(\ln 7.3890 . . .=2.\) $$e^{1.3}=3.6692 . . .$$

2 step solution

Problem 71

Solve the exponential equation algebraically. Round your result to three decimal places. Use a graphing utility to verify your answer. $$e^{2 x}-4 e^{x}-5=0$$

4 step solution

Problem 71

Complete the table to determine the balance \(A\) for \(\$ 12,000\) invested at rate \(r\) for \(t\) years, compounded continuously.. $$\begin{array}{|c|c|c|c|c|c|c|} \hline t & 1 & 10 & 20 & 30 & 40 & 50 \\ \hline A & & & & & & \\ \hline \end{array}$$ $$r=3.5 \%$$

3 step solution

Problem 72

Use the properties of logarithms to condense the expression.$$\log _{5} 8-\log _{5} t$$.

4 step solution

Problem 72

Write the exponential equation in logarithmic form. For example, the logarithmic form of \(e^{2}=7.3890 . . .\) is \(\ln 7.3890 . . .=2.\) $$e^{2.5}=12.1824 . . .$$

2 step solution

Problem 72

Solve the exponential equation algebraically. Round your result to three decimal places. Use a graphing utility to verify your answer. $$e^{2 x}-e^{x}-6=0$$

4 step solution

Problem 72

Complete the table to determine the balance \(A\) for \(\$ 12,000\) invested at rate \(r\) for \(t\) years, compounded continuously.. $$\begin{array}{|c|c|c|c|c|c|c|} \hline t & 1 & 10 & 20 & 30 & 40 & 50 \\ \hline A & & & & & & \\ \hline \end{array}$$ $$r=2.5 \%$$

4 step solution

Problem 73

Use the Leading Coefficient Test to determine the right-hand and left-hand behavior of the graph of the polynomial function. $$f(x)=2 x^{3}-3 x^{2}+x-1$$

3 step solution

Problem 73

Use the properties of logarithms to condense the expression.$$4 \log _{3}(x+2)$$.

2 step solution

Problem 73

Write the exponential equation in logarithmic form. For example, the logarithmic form of \(e^{2}=7.3890 . . .\) is \(\ln 7.3890 . . .=2.\) $$\sqrt[3]{e}=1.3956 . . . $$

3 step solution

Problem 73

Solve the exponential equation algebraically. Round your result to three decimal places. Use a graphing utility to verify your answer. $$e^{x}=e^{x^{2}-2}$$

4 step solution

Problem 73

You build an annuity by investing \(P\) dollars every month at interest rate \(r,\) compounded monthly. Find the amount \(A\) accrued after \(n\) months using the formula. \(A=P\left[\frac{(1+r / 12)^{n}-1}{r / 12}\right],\) where \(r\) is in decimal form. $$P=\mathrm{S} 25, r=0.12, n=48 \mathrm{months}$$

3 step solution

Problem 74

Use the Leading Coefficient Test to determine the right-hand and left-hand behavior of the graph of the polynomial function. $$f(x)=5-x^{2}-4 x^{4}$$

3 step solution

Problem 74

Use the properties of logarithms to condense the expression.$$\frac{5}{2} \log _{7}(z-4)$$.

2 step solution

Problem 74

Write the exponential equation in logarithmic form. For example, the logarithmic form of \(e^{2}=7.3890 . . .\) is \(\ln 7.3890 . . .=2.\) $$\frac{1}{e^{4}}=0.0183. . . $$

2 step solution

Problem 74

Solve the exponential equation algebraically. Round your result to three decimal places. Use a graphing utility to verify your answer. $$e^{2 x}=e^{x^{2}-8}$$

4 step solution

Problem 74

You build an annuity by investing \(P\) dollars every month at interest rate \(r,\) compounded monthly. Find the amount \(A\) accrued after \(n\) months using the formula. \(A=P\left[\frac{(1+r / 12)^{n}-1}{r / 12}\right],\) where \(r\) is in decimal form. $$P=\$ 100, r=0.09, n=60 \text { months }$$

4 step solution

Problem 75

Use the Leading Coefficient Test to determine the right-hand and left-hand behavior of the graph of the polynomial function. $$g(x)=-1.6 x^{5}+4 x^{2}-2$$

3 step solution

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