Chapter 4

College Algebra and Calculus: An Applied Approach · 373 exercises

Problem 16

Write the logarithm in terms of natural logarithms.\(\log _{10} 20\)

3 step solution

Problem 16

Use the definition of a logarithm to write the equation in logarithmic form. For example, the logarithmic form of \(2^{3}=8\) is \(\log _{2} 8=3$$e^{-x}=2\)

4 step solution

Problem 17

Classify the model as an exponential growth model or an exponential decay model.\(y=3 e^{0.5 t}\)

3 step solution

Problem 17

Apply the Inverse Property of logarithmic or exponential functions to simplify the expression.\(-8+e^{\ln x^{3}}\)

3 step solution

Problem 17

Write the logarithm in terms of natural logarithms.\(\log _{3} n\)

3 step solution

Problem 17

Use the definition of a logarithm to write the equation in exponential form. For example, the exponential form of \(\log _{5} 125=3\) is \(5^{3}=125\).\(\log _{4} 16=2\)

3 step solution

Problem 18

Classify the model as an exponential growth model or an exponential decay model.\(y=2 e^{-0.6 t}\)

2 step solution

Problem 18

Apply the Inverse Property of logarithmic or exponential functions to simplify the expression.\(-1+\ln e^{2 x}\)

3 step solution

Problem 18

Write the logarithm in terms of natural logarithms.\(\log _{2} m\)

2 step solution

Problem 18

Use the definition of a logarithm to write the equation in exponential form. For example, the exponential form of \(\log _{5} 125=3\) is \(5^{3}=125\).\(\log _{10} 1000=3\)

2 step solution

Problem 19

Classify the model as an exponential growth model or an exponential decay model.\(y=20 e^{-1.5 t}\)

2 step solution

Problem 19

Apply the Inverse Property of logarithmic or exponential functions to simplify the expression.\(10^{\log _{10}(x+5)}\)

2 step solution

Problem 19

Write the logarithm in terms of natural logarithms.\(\log _{1 / 5} x\)

3 step solution

Problem 19

Use the definition of a logarithm to write the equation in exponential form. For example, the exponential form of \(\log _{5} 125=3\) is \(5^{3}=125\).\(\log _{2} \frac{1}{2}=-1\)

3 step solution

Problem 19

Sketch the graph of the function.\(g(x)=4^{x}\)

3 step solution

Problem 20

Classify the model as an exponential growth model or an exponential decay model.\(y=4 e^{0.07 t}\)

2 step solution

Problem 20

Apply the Inverse Property of logarithmic or exponential functions to simplify the expression.\(10^{\log _{10}\left(x^{2}+7 x+10\right)}\)

2 step solution

Problem 20

Write the logarithm in terms of natural logarithms.\(\log _{1 / 3} x\)

2 step solution

Problem 20

Use the definition of a logarithm to write the equation in exponential form. For example, the exponential form of \(\log _{5} 125=3\) is \(5^{3}=125\).\(\log _{3} \frac{1}{9}=-2\)

3 step solution

Problem 20

Sketch the graph of the function.\(f(x)=\left(\frac{3}{2}\right)^{x}\)

3 step solution

Problem 21

Apply the Inverse Property of logarithmic or exponential functions to simplify the expression.\(2^{\log _{2} x^{2}}\)

2 step solution

Problem 21

Use the definition of a logarithm to write the equation in exponential form. For example, the exponential form of \(\log _{5} 125=3\) is \(5^{3}=125\).\(\ln e=1\)

2 step solution

Problem 21

Sketch the graph of the function.\(f(x)=4^{-x}\)

4 step solution

Problem 22

Apply the Inverse Property of logarithmic or exponential functions to simplify the expression.\(9^{\log _{9}(3 x+7)}\)

2 step solution

Problem 22

Write the logarithm in terms of natural logarithms.\(\log _{x} \frac{3}{4}\)

2 step solution

Problem 22

Use the definition of a logarithm to write the equation in exponential form. For example, the exponential form of \(\log _{5} 125=3\) is \(5^{3}=125\).\(\ln \frac{1}{e}=-1\)

3 step solution

Problem 22

Sketch the graph of the function.\(h(x)=\left(\frac{3}{2}\right)^{-x}\)

4 step solution

Problem 23

Solve the exponential equation algebraically. Approximate the result to three decimal places.\(3 e^{x}=9\)

3 step solution

Problem 23

Write the logarithm in terms of natural logarithms.\(\log _{2.6} x\)

2 step solution

Problem 23

Use the definition of a logarithm to write the equation in exponential form. For example, the exponential form of \(\log _{5} 125=3\) is \(5^{3}=125\).\(\log _{5} 0.2=-1\)

3 step solution

Problem 23

Sketch the graph of the function.\(h(x)=4^{x-3}\)

3 step solution

Problem 24

Solve the exponential equation algebraically. Approximate the result to three decimal places.\(5 e^{x}=20\)

5 step solution

Problem 24

Write the logarithm in terms of natural logarithms.\(\log _{7.1} x\)

3 step solution

Problem 24

Use the definition of a logarithm to write the equation in exponential form. For example, the exponential form of \(\log _{5} 125=3\) is \(5^{3}=125\).\(\log _{10} 0.1=-1\)

2 step solution

Problem 24

Sketch the graph of the function.\(g(x)=\left(\frac{3}{2}\right)^{x+2}\)

3 step solution

Problem 25

Population The population \(P\) of a city is given by \(P=120,000 e^{0.016 t}\) where \(t\) represents the year, with \(t=0\) corresponding to 2000\. Sketch the graph of this equation. Use the model to predict the year in which the population of the city will reach about 180,000

3 step solution

Problem 25

Solve the exponential equation algebraically. Approximate the result to three decimal places.\(2\left(3^{x}\right)=16\)

4 step solution

Problem 25

Evaluate the logarithm. Round your result to three decimal places.\(\log _{2} 6\)

3 step solution

Problem 25

Use the definition of a logarithm to write the equation in exponential form. For example, the exponential form of \(\log _{5} 125=3\) is \(5^{3}=125\).\(\log _{27} 3=\frac{1}{3}\)

2 step solution

Problem 25

Sketch the graph of the function.\(g(x)=4^{-x}-2\)

3 step solution

Problem 26

Solve the exponential equation algebraically. Approximate the result to three decimal places.\(3\left(4^{x}\right)=81\)

4 step solution

Problem 26

Evaluate the logarithm. Round your result to three decimal places.\(\log _{8} 3\)

3 step solution

Problem 26

Use the definition of a logarithm to write the equation in exponential form. For example, the exponential form of \(\log _{5} 125=3\) is \(5^{3}=125\).\(\log _{8} 2=\frac{1}{3}\)

2 step solution

Problem 26

Sketch the graph of the function.\(f(x)=\left(\frac{3}{2}\right)^{-x}+2\)

3 step solution

Problem 27

Bacteria Growth The number \(N\) of bacteria in a culture is given by the model \(N=100 e^{k t}\), where \(t\) is the time (in hours), with \(t=0\) corresponding to the time when \(N=100\). When \(t=6\), there are 140 bacteria. How long does it take the bacteria population to double in size? To triple in size?

3 step solution

Problem 27

Solve the exponential equation algebraically. Approximate the result to three decimal places.\(e^{x}-9=19\)

3 step solution

Problem 27

Evaluate the logarithm. Round your result to three decimal places.\(\log _{27} 35\)

3 step solution

Problem 27

Evaluate the expression without using a calculator.\(\log _{3} 9\)

2 step solution

Problem 27

Sketch the graph of the function.\(y=2^{-x^{2}}\)

3 step solution

Problem 28

Bacteria Growth The number \(N\) of bacteria in a culture is given by the model \(N=250 e^{k t}\), where \(t\) is the time (in hours), with \(t=0\) corresponding to the time when \(N=250\). When \(t=10\), there are 320 bacteria. How long does it take the bacteria population to double in size? To triple in size?

3 step solution

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