Chapter 10
College Algebra and Calculus: An Applied Approach · 279 exercises
Problem 15
In Exercises, use a graphing utility to graph the function. Be sure to choose an appropriate viewing window. $$ N(t)=500 e^{-0.2 t} $$
4 step solution
Problem 16
In Exercises, find the derivative of the function. $$ y=x^{2} e^{x}-2 x e^{x}+2 e^{x} $$
4 step solution
Problem 16
In Exercises, sketch the graph of the function. $$ y=5+\ln x $$
3 step solution
Problem 17
In Exercises, find the derivative of the function. $$ y=\ln \frac{x}{x+1} $$
3 step solution
Problem 17
In Exercises, sketch the graph of the function. $$ y=3 \ln x $$
3 step solution
Problem 17
In Exercises, determine an equation of the tangent line to the function at the given point. $$ y=e^{-2 x+x^{2}}, \quad(2,1) $$
3 step solution
Problem 17
In Exercises, use a graphing utility to graph the function. Be sure to choose an appropriate viewing window. $$ g(x)=\frac{2}{1+e^{x^{2}}} $$
3 step solution
Problem 18
Find the half-life of a radioactive material if after 1 year \(99.57 \%\) of the initial amount remains.
4 step solution
Problem 18
In Exercises, find the derivative of the function. $$ y=\ln \frac{x^{2}}{x^{2}+1} $$
4 step solution
Problem 18
In Exercises, sketch the graph of the function. $$ y=\frac{1}{4} \ln x $$
3 step solution
Problem 18
In Exercises, determine an equation of the tangent line to the function at the given point. $$ g(x)=e^{x^{3}}, \quad\left(-1, \frac{1}{e}\right) $$
3 step solution
Problem 18
In Exercises, use a graphing utility to graph the function. Be sure to choose an appropriate viewing window. $$ g(x)=\frac{10}{1+e^{-x}} $$
4 step solution
Problem 19
\({ }^{14} \mathrm{C}\) dating assumes that the carbon dioxide on the Earth today has the same radioactive content as it did centuries ago. If this is true, then the amount of \({ }^{14} \mathrm{C}\) absorbed by a tree that grew several centuries ago should be the same as the amount of \({ }^{14} \mathrm{C}\) absorbed by a similar tree today. A piece of ancient charcoal contains only \(15 \%\) as much of the radioactive carbon as a piece of modern charcoal. How long ago was the tree burned to make the ancient charcoal? (The half-life of \({ }^{14} \mathrm{C}\) is 5715 years.)
4 step solution
Problem 19
In Exercises, find the derivative of the function. $$ y=\ln \sqrt[3]{\frac{x-1}{x+1}} $$
7 step solution
Problem 19
In Exercises, determine an equation of the tangent line to the function at the given point. $$ y=x^{2} e^{-x}, \quad\left(2, \frac{4}{e^{2}}\right) $$
3 step solution
Problem 19
In Exercises, use a graphing utility to graph the function. Determine whether the function has any horizontal asymptotes and discuss the continuity of the function. $$ f(x)=\frac{e^{x}+e^{-x}}{2} $$
4 step solution
Problem 20
In Exercises, find the derivative of the function. $$ y=\ln \sqrt{\frac{x+1}{x-1}} $$
3 step solution
Problem 20
In Exercises, analytically show that the functions are inverse functions. Then use a graphing utility to show this graphically. $$ \begin{aligned} &f(x)=e^{x}-1 \\ &g(x)=\ln (x+1) \end{aligned} $$
3 step solution
Problem 20
In Exercises, determine an equation of the tangent line to the function at the given point. $$ y=\frac{x}{e^{2 x}}, \quad\left(1, \frac{1}{e^{2}}\right) $$
3 step solution
Problem 20
In Exercises, use a graphing utility to graph the function. Determine whether the function has any horizontal asymptotes and discuss the continuity of the function. $$ f(x)=\frac{e^{x}-e^{-x}}{2} $$
3 step solution
Problem 21
In Exercises, find the derivative of the function. $$ y=\ln \frac{\sqrt{4+x^{2}}}{x} $$
4 step solution
Problem 21
In Exercises, analytically show that the functions are inverse functions. Then use a graphing utility to show this graphically. $$ \begin{aligned} &f(x)=e^{2 x-1} \\ &g(x)=\frac{1}{2}+\ln \sqrt{x} \end{aligned} $$
2 step solution
Problem 21
In Exercises, determine an equation of the tangent line to the function at the given point. $$ y=\left(e^{2 x}+1\right)^{3}, \quad(0,8) $$
3 step solution
Problem 21
In Exercises, use a graphing utility to graph the function. Determine whether the function has any horizontal asymptotes and discuss the continuity of the function. $$ f(x)=\frac{2}{1+e^{1 / x}} $$
4 step solution
Problem 22
In Exercises, find exponential models \(y_{1}=C e^{k_{1} t}\) and \(y_{2}=C(2)^{k_{2} t}\) that pass through the points. Compare the values of \(k_{1}\) and \(k_{2} .\) Briefly explain your results. $$ (0,8),\left(20, \frac{1}{2}\right) $$
3 step solution
Problem 22
In Exercises, find the derivative of the function. $$ y=\ln \left(x \sqrt{4+x^{2}}\right) $$
5 step solution
Problem 22
In Exercises, determine an equation of the tangent line to the function at the given point. $$ y=\left(e^{4 x}-2\right)^{2}, \quad(0,1) $$
3 step solution
Problem 22
In Exercises, use a graphing utility to graph the function. Determine whether the function has any horizontal asymptotes and discuss the continuity of the function. $$ f(x)=\frac{2}{1+2 e^{-0.2 x}} $$
3 step solution
Problem 23
The number of a certain type of bacteria increases continuously at a rate proportional to the number present. There are 150 present at a given time and 450 present 5 hours later. (a) How many will there be 10 hours after the initial time? (b) How long will it take for the population to double? (c) Does the answer to part (b) depend on the starting time? Explain your reasoning.
4 step solution
Problem 23
In Exercises, find the derivative of the function. $$ g(x)=e^{-x} \ln x $$
3 step solution
Problem 23
In Exercises, apply the inverse properties of logarithmic and exponential functions to simplify the expression. $$ \ln e^{x^{2}} $$
2 step solution
Problem 23
In Exercises, find \(d y / d x\) implicitly. $$ x e^{y}-10 x+3 y=0 $$
3 step solution
Problem 23
In Exercises, use a graphing utility to graph the function. $$ y=2^{x-1} $$
5 step solution
Problem 24
In Exercises, find the derivative of the function. $$ f(x)=x \ln e^{x^{2}} $$
3 step solution
Problem 24
In Exercises, apply the inverse properties of logarithmic and exponential functions to simplify the expression. $$ \ln e^{2 x-1} $$
2 step solution
Problem 24
In Exercises, find \(d y / d x\) implicitly. $$ x^{2} y-e^{y}-4=0 $$
4 step solution
Problem 24
Use a graphing utility to graph the function. Describe the shape of the graph for very large and very small values of \(x\). (a) \(f(x)=\frac{8}{1+e^{-0.5 x}}\) (b) \(g(x)=\frac{8}{1+e^{-0.5 / x}}\)
4 step solution
Problem 24
In Exercises, use a graphing utility to graph the function. $$ y=4^{x}+3 $$
3 step solution
Problem 25
In Exercises, find the derivative of the function. $$ g(x)=\ln \frac{e^{x}+e^{-x}}{2} $$
4 step solution
Problem 25
In Exercises, apply the inverse properties of logarithmic and exponential functions to simplify the expression. $$ e^{\ln (5 x+2)} $$
2 step solution
Problem 25
In Exercises, find \(d y / d x\) implicitly. $$ x^{2} e^{-x}+2 y^{2}-x y=0 $$
4 step solution
Problem 25
In Exercises, use a graphing utility to graph the function. $$ y=-2^{x} $$
3 step solution
Problem 26
In Exercises, find the derivative of the function. $$ f(x)=\ln \frac{1+e^{x}}{1-e^{x}} $$
5 step solution
Problem 26
In Exercises, apply the inverse properties of logarithmic and exponential functions to simplify the expression. $$ e^{\ln \sqrt{x}} $$
3 step solution
Problem 26
In Exercises, find \(d y / d x\) implicitly. $$ e^{x y}+x^{2}-y^{2}=10 $$
3 step solution
Problem 26
In Exercises, use a graphing utility to graph the function. $$ y=-5^{x} $$
3 step solution
Problem 27
In Exercises, apply the inverse properties of logarithmic and exponential functions to simplify the expression. $$ -1+\ln e^{2 x} $$
3 step solution
Problem 27
In Exercises, find the second derivative. $$ f(x)=2 e^{3 x}+3 e^{-2 x} $$
2 step solution
Problem 27
In Exercises, use a graphing utility to graph the function. $$ y=3^{-x^{2}} $$
5 step solution
Problem 28
In Exercises, apply the inverse properties of logarithmic and exponential functions to simplify the expression. $$ -8+e^{\ln x^{3}} $$
3 step solution