Chapter 5

College Algebra with Modeling and Visualization · 407 exercises

Problem 38

Find \(C\) and a so that \(f(x)=C a^{x}\) models the situation described. State what the variable \(x\) represents in your formula. (Answers may vary.) A fish population is initially 6000 and decreases by half each year.

4 step solution

Problem 38

Modeling Decide if the situation could be modeled by a one-to-one function. The cumulative numbers of AIDS cases from 1980 to present

5 step solution

Problem 39

Simplify the expression. $$\log _{8} 64$$

5 step solution

Problem 39

Tire Pressure The pressure in a tire with a leak is 30 pounds per square inch initially and can be modeled by \(f(x)=30(0.9)^{x}\) after \(x\) minutes. What is the tire's pressure after 9.5 minutes?

5 step solution

Problem 39

Modeling Decide if the situation could be modeled by a one-to-one function. The population of the United States from 1980 to 2000

5 step solution

Problem 40

Simplify the expression. $$\text { In } \sqrt[3] e$$

5 step solution

Problem 40

Population The population of California was about 38 million in 2007 and increasing by \(1.6 \%\) each year. Estimate the population of California in 2012 .

4 step solution

Problem 40

(Refer to Examples 5 and \(6 .\) ) Write the expression as a logarithm of a single expression. $$ \log _{3} 5-\log _{3} 10-\log _{3} \frac{1}{2} $$

3 step solution

Problem 40

Modeling Decide if the situation could be modeled by a one-to-one function. The height \(y\) of a stone thrown upward after \(x\) seconds

4 step solution

Problem 41

Simplify the expression. $$\log _{1 / 2}\left(\frac{1}{4}\right)$$

5 step solution

Problem 41

Approximate \(f(x)\) to four decimal places. $$ f(x)=4 e^{-1.2 x}, \quad x=-2.4 $$

5 step solution

Problem 41

Exercises \(41-52:\) For the given \(g(x),\) evaluate each of the following. $$ \begin{array}{lllll} \text { (a) } g(-3) & \text { (b) } g(b) & \text { (c) } g\left(x^{3}\right) & \text { (d) } g(2 x-3) \end{array} $$ $$ g(x)=2 x+1 $$

4 step solution

Problem 41

Find a symbolic representation for \(f^{-1}(x).\) $$ f(x)=\sqrt[3]{x} $$

4 step solution

Problem 42

Simplify the expression. $$\log _{1 / 3}\left(\frac{1}{27}\right)$$

5 step solution

Problem 42

Approximate \(f(x)\) to four decimal places. $$ f(x)=-2.1 e^{-0.71 x}, \quad x=1.9 $$

4 step solution

Problem 42

Exercises \(41-52:\) For the given \(g(x),\) evaluate each of the following. $$ \begin{array}{lllll} \text { (a) } g(-3) & \text { (b) } g(b) & \text { (c) } g\left(x^{3}\right) & \text { (d) } g(2 x-3) \end{array} $$ $$ g(x)=5-\frac{1}{2} x $$

4 step solution

Problem 42

Find a symbolic representation for \(f^{-1}(x).\) $$ f(x)=2 x $$

4 step solution

Problem 43

Simplify the expression. $$\log _{1 / 6} 36$$

5 step solution

Problem 43

Approximate \(f(x)\) to four decimal places. $$ f(x)=\frac{1}{2}\left(e^{x}-e^{-x}\right), \quad x=-0.7 $$

6 step solution

Problem 43

(Refer to Examples 5 and \(6 .\) ) Write the expression as a logarithm of a single expression. $$ \ln x^{6}-\ln x^{3} $$

3 step solution

Problem 43

Exercises \(41-52:\) For the given \(g(x),\) evaluate each of the following. $$ \begin{array}{lllll} \text { (a) } g(-3) & \text { (b) } g(b) & \text { (c) } g\left(x^{3}\right) & \text { (d) } g(2 x-3) \end{array} $$ $$ g(x)=2(x+3)^{2}-4 $$

4 step solution

Problem 43

Find a symbolic representation for \(f^{-1}(x).\) $$ f(x)=-2 x+10 $$

4 step solution

Problem 44

Simplify the expression. $$\log _{1 / 4} 64$$

5 step solution

Problem 44

Approximate \(f(x)\) to four decimal places. $$ f(x)=4\left(e^{-0.3 x}-e^{-0.6 x}\right), \quad x=1.6 $$

6 step solution

Problem 44

Exercises \(41-52:\) For the given \(g(x),\) evaluate each of the following. $$ \begin{array}{lllll} \text { (a) } g(-3) & \text { (b) } g(b) & \text { (c) } g\left(x^{3}\right) & \text { (d) } g(2 x-3) \end{array} $$ $$ g(x)=-(x-1)^{2} $$

4 step solution

Problem 44

Find a symbolic representation for \(f^{-1}(x).\) $$ f(x)=x^{3}+2 $$

4 step solution

Problem 45

Simplify the expression. $$\log _{a} \frac{1}{a}$$

4 step solution

Problem 45

Sketch a graph of \(y=f(x)\) $$ f(x)=2^{x} $$

4 step solution

Problem 45

Exercises \(41-52:\) For the given \(g(x),\) evaluate each of the following. $$ \begin{array}{lllll} \text { (a) } g(-3) & \text { (b) } g(b) & \text { (c) } g\left(x^{3}\right) & \text { (d) } g(2 x-3) \end{array} $$ $$ g(x)=\frac{1}{2} x^{2}+3 x-1 $$

4 step solution

Problem 45

Find a symbolic representation for \(f^{-1}(x).\) $$ f(x)=3 x-1 $$

5 step solution

Problem 46

Simplify the expression. $$\log _{a}\left(a^{2} \cdot a^{3}\right)$$

3 step solution

Problem 46

Sketch a graph of \(y=f(x)\) $$ f(x)=4^{x} $$

5 step solution

Problem 46

Exercises \(41-52:\) For the given \(g(x),\) evaluate each of the following. $$ \begin{array}{lllll} \text { (a) } g(-3) & \text { (b) } g(b) & \text { (c) } g\left(x^{3}\right) & \text { (d) } g(2 x-3) \end{array} $$ $$ g(x)=2 x^{2}-x-9 $$

4 step solution

Problem 46

Find a symbolic representation for \(f^{-1}(x).\) $$ f(x)=\frac{x-1}{2} $$

5 step solution

Problem 47

Sketch a graph of \(y=f(x)\) $$ f(x)=3^{-x} $$

4 step solution

Problem 47

Exercises \(41-52:\) For the given \(g(x),\) evaluate each of the following. $$ \begin{array}{lllll} \text { (a) } g(-3) & \text { (b) } g(b) & \text { (c) } g\left(x^{3}\right) & \text { (d) } g(2 x-3) \end{array} $$ $$ g(x)=\sqrt{x+4} $$

4 step solution

Problem 47

Find a symbolic representation for \(f^{-1}(x).\) $$ f(x)=2 x^{3}-5 $$

6 step solution

Problem 48

Simplify the expression. $$\text { ln } \sqrt{e}$$

3 step solution

Problem 48

Sketch a graph of \(y=f(x)\) $$ f(x)=3\left(2^{-x}\right) $$

5 step solution

Problem 48

Exercises \(41-52:\) For the given \(g(x),\) evaluate each of the following. $$ \begin{array}{lllll} \text { (a) } g(-3) & \text { (b) } g(b) & \text { (c) } g\left(x^{3}\right) & \text { (d) } g(2 x-3) \end{array} $$ $$ g(x)=\sqrt{2-x} $$

4 step solution

Problem 48

Find a symbolic representation for \(f^{-1}(x).\) $$ f(x)=1-\frac{1}{2} x^{3} $$

5 step solution

Problem 49

Simplify the expression. $$\log _{2} \frac{1}{16}$$

5 step solution

Problem 49

Sketch a graph of \(y=f(x)\) $$ f(x)=2\left(\frac{1}{3}\right)^{x} $$

5 step solution

Problem 49

Exercises \(41-52:\) For the given \(g(x),\) evaluate each of the following. $$ \begin{array}{lllll} \text { (a) } g(-3) & \text { (b) } g(b) & \text { (c) } g\left(x^{3}\right) & \text { (d) } g(2 x-3) \end{array} $$ $$ g(x)=|3 x-1|+4 $$

4 step solution

Problem 49

Find a symbolic representation for \(f^{-1}(x).\) $$ f(x)=x^{2}-1, x \geq 0 $$

5 step solution

Problem 50

Simplify the expression. $$\log _{8} 8^{k}$$

3 step solution

Problem 50

Sketch a graph of \(y=f(x)\) $$ f(x)=2\left(3^{x}\right) $$

5 step solution

Problem 50

Exercises \(41-52:\) For the given \(g(x),\) evaluate each of the following. $$ \begin{array}{lllll} \text { (a) } g(-3) & \text { (b) } g(b) & \text { (c) } g\left(x^{3}\right) & \text { (d) } g(2 x-3) \end{array} $$ $$ g(x)=2|1-x|-7 $$

4 step solution

Problem 50

Find a symbolic representation for \(f^{-1}(x).\) $$ f(x)=(x+2)^{2}, x \leq-2 $$

5 step solution

Problem 51

Sketch a graph of \(y=f(x)\) $$ f(x)=\left(\frac{1}{2}\right)^{x} $$

4 step solution

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