Chapter 8
College Algebra and Calculus: An Applied Approach · 242 exercises
Problem 20
In Exercises, find the absolute extrema of the function on the closed interval. Use a graphing utility to verify your results. $$ f(x)=\frac{1}{3}(2 x+5), \quad[0,5] $$
4 step solution
Problem 20
In Exercises, find the critical numbers and the open intervals on which the function is increasing or decreasing. Then use a graphing utility to graph the function. $$ y=x^{2 / 3}-4 $$
4 step solution
Problem 20
In Exercises, find the third derivative of the function. $$ f(x)=\left(x^{3}-6\right)^{4} $$
3 step solution
Problem 21
In Exercises, find all relative extrema of the function. Use the Second- Derivative Test when applicable. $$ f(x)=\frac{x}{x-1} $$
3 step solution
Problem 21
In Exercises, find the absolute extrema of the function on the closed interval. Use a graphing utility to verify your results. $$ f(x)=5-2 x^{2}, \quad[0,3] $$
4 step solution
Problem 21
In Exercises, find the critical numbers and the open intervals on which the function is increasing or decreasing. Then use a graphing utility to graph the function. $$ g(x)=(x-1)^{1 / 3} $$
4 step solution
Problem 21
A (square) baseball diamond has sides that are 90 feet long (see figure). A player 26 feet from third base is running at a speed of 30 feet per second. At what rate is the player's distance from home plate changing?
5 step solution
Problem 21
In Exercises, find the third derivative of the function. $$ f(x)=\frac{3}{16 x^{2}} $$
3 step solution
Problem 22
In Exercises, find all relative extrema of the function. Use the Second- Derivative Test when applicable. $$ f(x)=\frac{x}{x^{2}-1} $$
4 step solution
Problem 22
In Exercises, find the absolute extrema of the function on the closed interval. Use a graphing utility to verify your results. $$ f(x)=x^{2}+2 x-4, \quad[-1,1] $$
4 step solution
Problem 22
In Exercises, find the critical numbers and the open intervals on which the function is increasing or decreasing. Then use a graphing utility to graph the function. $$ g(x)=(x-1)^{2 / 3} $$
3 step solution
Problem 22
A retail sporting goods store estimates that weekly sales \(S\) and weekly advertising costs \(x\) are related by the equation \(S=2250+50 x+0.35 x^{2}\). The current weekly advertising costs are \(\$ 1500\), and these costs are increasing at a rate of \(\$ 125\) per week. Find the current rate of change of weekly sales.
3 step solution
Problem 22
In Exercises, find the third derivative of the function. $$ f(x)=\frac{1}{x} $$
3 step solution
Problem 23
In Exercise, use a graphing utility to estimate graphically all relative extrema of the function. $$ f(x)=\frac{1}{2} x^{4}-\frac{1}{3} x^{3}-\frac{1}{2} x^{2} $$
3 step solution
Problem 23
In Exercises, find the absolute extrema of the function on the closed interval. Use a graphing utility to verify your results. $$ f(x)=x^{3}-3 x^{2}, \quad[-1,3] $$
4 step solution
Problem 23
In Exercises, find the critical numbers and the open intervals on which the function is increasing or decreasing. Then use a graphing utility to graph the function. $$ f(x)=-2 x^{2}+4 x+3 $$
4 step solution
Problem 23
An accident at an oil drilling platform is causing a circular oil slick. The slick is \(0.08\) foot thick, and when the radius of the slick is 150 feet, the radius is increasing at the rate of \(0.5\) foot per minute. At what rate (in cubic feet per minute) is oil flowing from the site of the accident?
3 step solution
Problem 24
In Exercise, use a graphing utility to estimate graphically all relative extrema of the function. $$ f(x)=-\frac{1}{3} x^{5}-\frac{1}{2} x^{4}+x $$
4 step solution
Problem 24
In Exercises, find the absolute extrema of the function on the closed interval. Use a graphing utility to verify your results. $$ f(x)=x^{3}-12 x, \quad[0,4] $$
4 step solution
Problem 24
In Exercises, find the critical numbers and the open intervals on which the function is increasing or decreasing. Then use a graphing utility to graph the function. $$ f(x)=x^{2}+8 x+10 $$
5 step solution
Problem 24
A company is increasing the production of a product at the rate of 25 units per week. The demand and cost functions for the product are given by \(p=50-0.01 x\) and \(C=4000+40 x-0.02 x^{2} .\) Find the rate of change of the profit with respect to time when the weekly sales are \(x=800\) units. Use a graphing utility to graph the profit function, and use the zoom and trace features of the graphing utility to verify your result.
4 step solution
Problem 24
In Exercises, find the given value. $$ f(x)=9-x^{2} \quad f^{\prime \prime}(-\sqrt{5}) $$
3 step solution
Problem 25
In Exercise, use a graphing utility to estimate graphically all relative extrema of the function. $$ f(x)=5+3 x^{2}-x^{3} $$
3 step solution
Problem 25
In Exercises, find the absolute extrema of the function on the closed interval. Use a graphing utility to verify your results. $$ h(s)=\frac{1}{3-s}, \quad[0,2] $$
3 step solution
Problem 25
In Exercises, find the critical numbers and the open intervals on which the function is increasing or decreasing. Then use a graphing utility to graph the function. $$ y=3 x^{3}+12 x^{2}+15 x $$
4 step solution
Problem 25
The profit for a product is increasing at a rate of \(\$ 5600\) per week. The demand and cost functions for the product are given by \(p=6000-25 x\) and \(C=2400 x\) + 5200 . Find the rate of change of sales with respect to time when the weekly sales are \(x=44\) units.
5 step solution
Problem 26
In Exercise, use a graphing utility to estimate graphically all relative extrema of the function. $$ f(x)=3 x^{3}+5 x^{2}-2 $$
3 step solution
Problem 26
In Exercises, find the absolute extrema of the function on the closed interval. Use a graphing utility to verify your results. $$ h(t)=\frac{t}{t-2}, \quad[3,5] $$
4 step solution
Problem 26
In Exercises, find the critical numbers and the open intervals on which the function is increasing or decreasing. Then use a graphing utility to graph the function. $$ y=x^{3}-3 x+2 $$
4 step solution
Problem 26
The annual cost (in millions of dollars) for a government agency to seize \(p \%\) of an illegal drug is given by \(C=\frac{528 p}{100-p}, 0 \leq p<100\) The agency's goal is to increase \(p\) by \(5 \%\) per year. Find the rates of change of the cost when (a) \(p=30 \%\) and (b) \(p=60 \%\). Use a graphing utility to graph \(C\). What happens to the graph of \(C\) as \(p\) approaches \(100 ?\)
3 step solution
Problem 27
In Exercises, find the absolute extrema of the function on the closed interval. Use a graphing utility to verify your results. $$ f(x)=3 x^{2 / 3}-2 x, \quad[-1,2] $$
4 step solution
Problem 27
In Exercises, find the critical numbers and the open intervals on which the function is increasing or decreasing. Then use a graphing utility to graph the function. $$ f(x)=x \sqrt{x+1} $$
3 step solution
Problem 28
In Exercises, find the absolute extrema of the function on the closed interval. Use a graphing utility to verify your results. $$ g(t)=\frac{t^{2}}{t^{2}+3}, \quad[-1,1] $$
4 step solution
Problem 28
In Exercises, find the critical numbers and the open intervals on which the function is increasing or decreasing. Then use a graphing utility to graph the function. $$ h(x)=x \sqrt[3]{x-1} $$
3 step solution
Problem 29
In Exercises, find the absolute extrema of the function on the closed interval. Use a graphing utility to verify your results. $$ h(t)=(t-1)^{2 / 3}, \quad[-7,2] $$
5 step solution
Problem 29
In Exercises, find the critical numbers and the open intervals on which the function is increasing or decreasing. Then use a graphing utility to graph the function. $$ f(x)=x^{4}-2 x^{3} $$
4 step solution
Problem 29
In Exercises, find the higher-order derivative. $$ f^{\prime}(x)=2 x^{2} $$
3 step solution
Problem 30
In Exercises, find the absolute extrema of the function on the closed interval. Use a graphing utility to verify your results. $$ g(x)=4\left(1+\frac{1}{x}+\frac{1}{x^{2}}\right), \quad[-4,5] $$
3 step solution
Problem 30
In Exercises, find the critical numbers and the open intervals on which the function is increasing or decreasing. Then use a graphing utility to graph the function. $$ f(x)=\frac{1}{i} x^{4}-2 x^{2} $$
4 step solution
Problem 30
In Exercises, find the higher-order derivative. $$ f^{\prime \prime}(x)=20 x^{3}-36 x^{2} $$
3 step solution
Problem 31
In Exercises, find the point(s) of inflection of the graph of the function. $$ f(x)=x^{3}-9 x^{2}+24 x-18 $$
5 step solution
Problem 31
In Exercises, find the critical numbers and the open intervals on which the function is increasing or decreasing. Then use a graphing utility to graph the function. $$ f(x)=\frac{x}{x^{2}+4} $$
4 step solution
Problem 31
In Exercises, find the higher-order derivative. $$ f^{\prime \prime \prime}(x)=(3 x-1) / x $$
3 step solution
Problem 32
In Exercises, find the point(s) of inflection of the graph of the function. $$ f(x)=x(6-x)^{2} $$
5 step solution
Problem 32
In Exercises, find the critical numbers and the open intervals on which the function is increasing or decreasing. Then use a graphing utility to graph the function. $$ f(x)=\frac{x^{2}}{x^{2}+4} $$
4 step solution
Problem 33
In Exercises, find the point(s) of inflection of the graph of the function. $$ f(x)=(x-1)^{3}(x-5) $$
4 step solution
Problem 33
In Exercises, use a graphing utility to find graphically the absolute extrema of the function on the closed interval. $$ f(x)=0.4 x^{3}-1.8 x^{2}+x-3, \quad[0,5] $$
4 step solution
Problem 33
In Exercises, find the critical numbers and the open intervals on which the function is increasing or decreasing. (Hint: Check for discontinuities.) Sketch the graph of the function. $$ f(x)=\frac{2 x}{16-x^{2}} $$
4 step solution
Problem 34
In Exercises, find the point(s) of inflection of the graph of the function. $$ f(x)=x^{4}-18 x^{2}+5 $$
5 step solution
Problem 34
In Exercises, use a graphing utility to find graphically the absolute extrema of the function on the closed interval. $$ f(x)=3.2 x^{5}+5 x^{3}-3.5 x, \quad[0,1] $$
3 step solution