Chapter 12

Algebra A Combined Function · 491 exercises

Problem 27

Solve each equation. $$ \log _{4}\left(x^{2}-3 x\right)=1 $$

6 step solution

Problem 27

Write each as a logarithmic equation. $$ 5^{1 / 2}=\sqrt{5} $$

4 step solution

Problem 27

By inspection, find the value for \(x\) that makes each statement true. \(2^{x}=8\)

4 step solution

Problem 27

Find the exact value of each logarithm. $$ \log 0.0001 $$

4 step solution

Problem 27

If \(f(x)=3 x, g(x)=\sqrt{x}\), and \(h(x)=x^{2}+2,\) write each function as a composition with \(f, g\), or \(h .\) $$ F(x)=9 x^{2}+2 $$

4 step solution

Problem 27

Each of the following functions is one-to-one. Find the inverse of each function and graph the function and its inverse on the same set of axes. $$ f(x)=\frac{1}{2} x-1 $$

6 step solution

Problem 27

Solve. $$ \frac{1}{4}=2^{3 x} $$

4 step solution

Problem 27

Write each as a single logarithm. Assume that variables represent positive numbers. $$ 3 \log _{5} x+6 \log _{5} z $$

3 step solution

Problem 28

Solve each equation. $$ \log _{8}\left(x^{2}-2 x\right)=1 $$

6 step solution

Problem 28

Write each as a logarithmic equation. $$ 4^{1 / 3}=\sqrt[3]{4} $$

3 step solution

Problem 28

By inspection, find the value for \(x\) that makes each statement true. \(3^{x}=9\)

2 step solution

Problem 28

Find the exact value of each logarithm. $$ \log 0.001 $$

2 step solution

Problem 28

If \(f(x)=3 x, g(x)=\sqrt{x}\), and \(h(x)=x^{2}+2,\) write each function as a composition with \(f, g\), or \(h .\) $$ H(x)=3 x^{2}+6 $$

4 step solution

Problem 28

Each of the following functions is one-to-one. Find the inverse of each function and graph the function and its inverse on the same set of axes. $$ f(x)=-\frac{1}{2} x+2 $$

6 step solution

Problem 28

Solve. $$ \frac{1}{27}=3^{2 x} $$

3 step solution

Problem 28

Write each as a single logarithm. Assume that variables represent positive numbers. $$ 2 \log _{7} y+6 \log _{7} z $$

2 step solution

Problem 29

Solve each equation. $$ \log _{2} x+\log _{2}(3 x+1)=1 $$

5 step solution

Problem 29

Find the value of each logarithmic expression. $$ \log _{2} 8 $$

5 step solution

Problem 29

By inspection, find the value for \(x\) that makes each statement true. \(5^{x}=\frac{1}{5}\)

4 step solution

Problem 29

Find the exact value of each logarithm. $$ \ln \sqrt{e} $$

5 step solution

Problem 29

If \(f(x)=3 x, g(x)=\sqrt{x}\), and \(h(x)=x^{2}+2,\) write each function as a composition with \(f, g\), or \(h .\) $$ G(x)=3 \sqrt{x} $$

3 step solution

Problem 29

Each of the following functions is one-to-one. Find the inverse of each function and graph the function and its inverse on the same set of axes. $$ f(x)=x^{3} $$

5 step solution

Problem 29

Solve. $$ 9^{x}=27 $$

4 step solution

Problem 29

Write each as a single logarithm. Assume that variables represent positive numbers. $$ \log _{4} 2+\log _{4} 10-\log _{4} 5 $$

5 step solution

Problem 30

Solve each equation. $$ \log _{3} x+\log _{3}(x-8)=2 $$

7 step solution

Problem 30

Find the value of each logarithmic expression. $$ \log _{3} 9 $$

4 step solution

Problem 30

By inspection, find the value for \(x\) that makes each statement true. \(4^{x}=1\)

3 step solution

Problem 30

Find the exact value of each logarithm. $$ \log \sqrt{10} $$

5 step solution

Problem 30

Each of the following functions is one-to-one. Find the inverse of each function and graph the function and its inverse on the same set of axes. $$ f(x)=x^{3}-1 $$

5 step solution

Problem 30

Solve. $$ 32^{x}=4 $$

4 step solution

Problem 30

Write each as a single logarithm. Assume that variables represent positive numbers. $$ \log _{6} 21+\log _{6} 2-\log _{6} 7 $$

3 step solution

Problem 31

Solve. The size of the wolf population at Isle Royale National Park increases according to the formula \(y=y_{0} e^{0.043 t} .\) In this formula, \(t\) is time in years and \(y_{0}\) is the initial population at time 0 . If the size of the current population is 83 wolves, find how many there should be in 5 years. Round to the nearest whole number.

7 step solution

Problem 31

Find the value of each logarithmic expression. $$ \log _{2} \frac{1}{4} $$

5 step solution

Problem 31

An item is on sale for \(40 \%\) off its original price. If it is then marked down an additional \(60 \%,\) does this mean the item is free? Discuss why or why not.

4 step solution

Problem 31

Solve each equation. Give an exact solution and a four-decimal-place approximation. $$ \log x=1.3 $$

4 step solution

Problem 31

Find \(f(x)\) and \(g(x)\) so that the given function \(h(x)=(f \circ g)(x)\). $$ h(x)=(x+2)^{2} $$

4 step solution

Problem 31

Find the inverse of each one-to-one function. $$ f(x)=\frac{x-2}{5} $$

5 step solution

Problem 31

Solve. $$ 27^{x+1}=9 $$

5 step solution

Problem 31

Write each as a single logarithm. Assume that variables represent positive numbers. $$ \log _{7} 6+\log _{7} 3-\log _{7} 4 $$

3 step solution

Problem 32

Solve. The number of victims of a flu epidemic is increasing according to the formula \(y=y_{0} e^{0.075 t}\). In this formula, is time in weeks and \(y_{0}\) is the given population at time 0 . If 20,000 people are currently infected, how many might be infected in 3 weeks? Round to the nearest whole number.

7 step solution

Problem 32

Find the value of each logarithmic expression. $$ \log _{2} \frac{1}{32} $$

4 step solution

Problem 32

Uranium U-232 has a half-life of 72 years. What eventually happens to a 10 gram sample? Does it ever completely decay and disappear? Discuss why or why not.

5 step solution

Problem 32

Solve each equation. Give an exact solution and a four-decimal-place approximation. $$ \log x=2.1 $$

4 step solution

Problem 32

Find the inverse of each one-to-one function. $$ f(x)=\frac{4 x-3}{2} $$

6 step solution

Problem 32

Solve. $$ 125^{x-2}=25 $$

4 step solution

Problem 32

Find \(f(x)\) and \(g(x)\) so that the given function \(h(x)=(f \circ g)(x)\). $$ h(x)=|x-1| $$

3 step solution

Problem 32

Write each as a single logarithm. Assume that variables represent positive numbers. $$ \log _{8} 5+\log _{8} 15-\log _{8} 20 $$

5 step solution

Problem 33

Solve. The population of the Cook Islands is decreasing according to the formula \(y=y_{0} e^{-0.0277 t}\). In this formula, \(t\) is time in years and \(y_{0}\) is the initial population at time 0 . If the size of the population in 2009 was \(11,870,\) use the formula to predict the population of Cook Islands in the year \(2025 .\) Round to the nearest whole number. (Source: The World Almanac)

5 step solution

Problem 33

Find the value of each logarithmic expression. $$ \log _{25} 5 $$

5 step solution

Problem 33

Solve each equation. Give an exact solution and a four-decimal-place approximation. $$ \ln x=1.4 $$

5 step solution

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