Chapter 5
Calculus A New Horizon · 139 exercises
Problem 21
Find: (a) the intervals on which \(f\) is increasing, (b) the intervals on which \(f\) is decreasing, (c) the open intervals on which \(f\) is concave up. (d) the open intervals on which \(f\) is concave down, and (e) the \(x\) -coordinates of all inflection points. $$f(x)=e^{-x^{2} / 2}$$
6 step solution
Problem 21
Use any method to find the relative extrema of the function \(f\). $$f(x)=x^{3}+5 x-2$$
4 step solution
Problem 22
Find: (a) the intervals on which \(f\) is increasing, (b) the intervals on which \(f\) is decreasing, (c) the open intervals on which \(f\) is concave up. (d) the open intervals on which \(f\) is concave down, and (e) the \(x\) -coordinates of all inflection points. $$f(x)=x e^{x^{2}}$$
5 step solution
Problem 22
The graph of the rational function crosses a horizontal asymptote. Give a complete graph of the function, and label the coordinates of the stationary points and inflection points. Show the horizontal and vertical asymptotes, and label the point(s) where the graph crosses a horizontal asymptote. Check your work with a graphing utility. $$2+\frac{3}{x}-\frac{1}{x^{3}}$$
6 step solution
Problem 22
Use any method to find the relative extrema of the function \(f\). $$f(x)=x^{4}-2 x^{2}+7$$
3 step solution
Problem 23
Find: (a) the intervals on which \(f\) is increasing, (b) the intervals on which \(f\) is decreasing, (c) the open intervals on which \(f\) is concave up. (d) the open intervals on which \(f\) is concave down, and (e) the \(x\) -coordinates of all inflection points. $$f(x)=\ln \left(1+x^{2}\right)$$
6 step solution
Problem 23
Use any method to find the relative extrema of the function \(f\). $$f(x)=x(x-1)^{2}$$
5 step solution
Problem 24
Find: (a) the intervals on which \(f\) is increasing, (b) the intervals on which \(f\) is decreasing, (c) the open intervals on which \(f\) is concave up. (d) the open intervals on which \(f\) is concave down, and (e) the \(x\) -coordinates of all inflection points. $$f(x)=x^{2} \ln x$$
6 step solution
Problem 24
Sketch the general shape of the graph of \(y=x^{1 / n},\) and then explain in words what happens to the shape of the graph as \(n\) increases if (a) \(n\) is a positive even integer (b) \(n\) is a positive odd integer.
5 step solution
Problem 24
Use any method to find the relative extrema of the function \(f\). $$f(x)=x^{4}+2 x^{3}$$
4 step solution
Problem 25
Analyze the trigonometric function \(f\) over the specified interval, stating where \(f\) is increasing. decreasing, concave up, and concave down, and stating the \(x\) coordinates of all inflection points. Confirm that your results are consistent with the graph of \(f\) generated with a graphing utility. $$f(x)=\cos x ;[0,2 \pi]$$
6 step solution
Problem 25
Use any method to find the relative extrema of the function \(f\). $$f(x)=2 x^{2}-x^{4}$$
4 step solution
Problem 26
Analyze the trigonometric function \(f\) over the specified interval, stating where \(f\) is increasing. decreasing, concave up, and concave down, and stating the \(x\) coordinates of all inflection points. Confirm that your results are consistent with the graph of \(f\) generated with a graphing utility. $$f(x)=\sin ^{2} 2 x ;[0, \pi]$$
6 step solution
Problem 26
Use any method to find the relative extrema of the function \(f\). $$f(x)=(2 x-1)^{5}$$
4 step solution
Problem 27
Analyze the trigonometric function \(f\) over the specified interval, stating where \(f\) is increasing. decreasing, concave up, and concave down, and stating the \(x\) coordinates of all inflection points. Confirm that your results are consistent with the graph of \(f\) generated with a graphing utility. $$f(x)=\tan x ;(-\pi / 2, \pi / 2)$$
6 step solution
Problem 27
Give a complete graph of the function, and identify the location of all critical points and inflection poir s. Check your work with a graphing utility. $$2 x+3 x^{2 / 3}$$
7 step solution
Problem 27
Use any method to find the relative extrema of the function \(f\). $$f(x)=x^{4 / 5}$$
4 step solution
Problem 28
Analyze the trigonometric function \(f\) over the specified interval, stating where \(f\) is increasing. decreasing, concave up, and concave down, and stating the \(x\) coordinates of all inflection points. Confirm that your results are consistent with the graph of \(f\) generated with a graphing utility. $$f(x)=2 x+\cot x ;(0, \pi)$$
5 step solution
Problem 28
Give a complete graph of the function, and identify the location of all critical points and inflection poir s. Check your work with a graphing utility. $$4 x-3 x^{4 / 3}$$
5 step solution
Problem 28
Use any method to find the relative extrema of the function \(f\). $$f(x)=2 x+x^{2 / 3}$$
4 step solution
Problem 29
Analyze the trigonometric function \(f\) over the specified interval, stating where \(f\) is increasing. decreasing, concave up, and concave down, and stating the \(x\) coordinates of all inflection points. Confirm that your results are consistent with the graph of \(f\) generated with a graphing utility. $$f(x)=\sin x \cos x ;[0, \pi]$$
6 step solution
Problem 29
Give a complete graph of the function, and identify the location of all critical points and inflection poir s. Check your work with a graphing utility. $$x \sqrt{3-x}$$
7 step solution
Problem 29
Use any method to find the relative extrema of the function \(f\). $$f(x)=\frac{x^{2}}{x^{2}+1}$$
5 step solution
Problem 30
Analyze the trigonometric function \(f\) over the specified interval, stating where \(f\) is increasing. decreasing, concave up, and concave down, and stating the \(x\) coordinates of all inflection points. Confirm that your results are consistent with the graph of \(f\) generated with a graphing utility. $$f(x)=\cos ^{2} x-2 \sin x ;[0,2 \pi]$$
7 step solution
Problem 30
Give a complete graph of the function, and identify the location of all critical points and inflection poir s. Check your work with a graphing utility. $$4 x^{1 / 3}-x^{4 / 3}$$
5 step solution
Problem 30
Use any method to find the relative extrema of the function \(f\). $$f(x)=\frac{x}{x+2}$$
4 step solution
Problem 31
In each part sketch a continuous curve \(y=f(x)\) with the stated properties. (a) \(f(2)=4, f^{\prime}(2)=0, f^{\prime \prime}(x)>0\) for all \(x\) (b) \(f(2)=4, f^{\prime}(2)=0, f^{\prime \prime}(x)<0\) for \(x<2, f^{\prime \prime}(x)>0\) for \(x>2\) (c) \(f(2)=4, f^{\prime \prime}(x)<0\) for \(x \neq 2\) and \(\lim _{x \rightarrow 2^{+}} f^{\prime}(x)=+\infty\) \(\lim _{x \rightarrow 2^{-}} f^{\prime}(x)=-\infty\)
6 step solution
Problem 31
Give a complete graph of the function, and identify the location of all critical points and inflection poir s. Check your work with a graphing utility. $$\frac{8(\sqrt{x}-1)}{x}$$
5 step solution
Problem 31
Use any method to find the relative extrema of the function \(f\). $$f(x)=\ln \left(1+x^{2}\right)$$
3 step solution
Problem 32
In each part sketch a continuous curve \(y=f(x)\) with the stated properties. (a) \(f(2)=4, \quad f^{\prime}(2)=0, \quad f^{\prime \prime}(x)<0\) for all \(x\) (b) \(f(2)=4, f^{\prime}(2)=0, f^{\prime \prime}(x)>0\) for \(x<2, f^{\prime \prime}(x)<0\) for \(x>2\) (c) \(f(2)=4, \quad f^{\prime \prime}(x)>0\) for \(x \neq 2\) and \(\lim _{x \rightarrow 2^{+}} f^{\prime}(x)=-\infty$$\lim _{x \rightarrow 2^{-}} f^{\prime}(x)=+\infty\)
6 step solution
Problem 32
Use any method to find the relative extrema of the function \(f\). $$f(x)=x^{2} e^{x}$$
4 step solution
Problem 33
In each part, assume that \(a\) is a constant and find the inflection points, if any. (a) \(f(x)=(x-a)^{3}\) (b) \(f(x)=(x-a)^{4}\)
6 step solution
Problem 33
Give a complete graph of the function, and identify the location of all relative extrema and inflection points. Check your work with a graphing utility. $$x+\sin x$$
6 step solution
Problem 33
Use any method to find the relative extrema of the function \(f\). $$f(x)=\left|x^{2}-4\right|$$
4 step solution
Problem 34
Give a complete graph of the function, and identify the location of all relative extrema and inflection points. Check your work with a graphing utility. $$x-\cos x$$
7 step solution
Problem 34
Use any method to find the relative extrema of the function \(f\). $$f(x)=\left\\{\begin{array}{ll} 9-x, & x \leq 3 \\\x^{2}-3, & x>3\end{array}\right.$$
5 step solution
Problem 35
If \(f\) is increasing on an interval \([0, b),\) then it follows from Definition
5.1.1 that \(f(0)
5 step solution
Problem 35
Find the relative extrema in the interval \(0
5 step solution
Problem 35
Give a complete graph of the function, and identify the location of all relative extrema and inflection points. Check your work with a graphing utility. $$\sin x+\cos x$$
7 step solution
Problem 36
If \(f\) is increasing on an interval \([0, b),\) then it follows from Definition
5.1.1 that \(f(0)
6 step solution
Problem 36
Find the relative extrema in the interval \(0
5 step solution
Problem 36
Give a complete graph of the function, and identify the location of all relative extrema and inflection points. Check your work with a graphing utility. $$\sqrt{3} \cos x+\sin x$$
7 step solution
Problem 37
Find the relative extrema in the interval \(0
4 step solution
Problem 37
Give a complete graph of the function, and identify the location of all relative extrema and inflection points. Check your work with a graphing utility. $$\sin ^{2} x, \quad 0 \leq x \leq 2 \pi$$
7 step solution
Problem 38
If \(f\) is increasing on an interval \([0, b),\) then it follows from Definition
5.1.1 that \(f(0)
6 step solution
Problem 38
Find the relative extrema in the interval \(0< x <2 \pi,\) and confirm that your results are consistent with the graph of \(f\) generated with a graphing utility. $$f(x)=\frac{\sin x}{2-\cos x}$$
6 step solution
Problem 38
Give a complete graph of the function, and identify the location of all
relative extrema and inflection points. Check your work with a graphing
utility.
$$x \tan x, \quad-\pi / 2
5 step solution
Problem 39
Use a graphing utility to generate the graphs of \(f^{\prime}\) and \(f^{\prime \prime}\) over the stated interval; then use those graphs to estimate the \(x\) -coordinates of the inflection points of \(f\), the intervals on which \(f\) is concave up or down, and the intervals on which \(f\) is increasing or decreasing. Check your estimates by graphing \(f\). $$f(x)=x^{4}-24 x^{2}+12 x, \quad-5 \leq x \leq 5$$
5 step solution
Problem 39
Use a graphing utility to make a conjecture about the relative extrema of \(f,\) and then check your conjecture using either the first or second derivative test. $$f(x)=x \ln x$$
5 step solution
Problem 40
Use a graphing utility to generate the graphs of \(f^{\prime}\) and \(f^{\prime \prime}\) over the stated interval; then use those graphs to estimate the \(x\) -coordinates of the inflection points of \(f\), the intervals on which \(f\) is concave up or down, and the intervals on which \(f\) is increasing or decreasing. Check your estimates by graphing \(f\). $$f(x)=\frac{1}{1+x^{2}}, \quad-5 \leq x \leq 5$$
5 step solution