Chapter 10
Applied Mathematics: For the Managerial, Life, and Social Sciences · 324 exercises
Problem 34
Use the information summarized in the table to sketch the graph of \(f\). \(f(x)=\frac{1}{9}\left(x^{4}-4 x^{3}\right)\) Domain: \((-\infty, \infty)\) Intercepts: \(x\) -intercepts: 0,\(4 ; y\) -intercept: 0 Asymptotes: None Intervals where \(f\) is \(\nearrow\) and \(\searrow: \nearrow\) on \((3, \infty)\); \(\searrow\) on \((-\infty, 0) \cup(0,3)\) Relative extrema: Rel. min. at \((3,-3)\) Concavity: Downward on \((0,2) ;\) upward on \((-\infty, 0) \cup(2, \infty)\) Points of inflection: \((0,0)\) and \(\left(2,-\frac{16}{9}\right)\)
5 step solution
Problem 34
Determine where the function is concave upward and where it is concave downward. $$ g(x)=\sqrt{x-2} $$
4 step solution
Problem 34
Find the interval(s) where the function is increasing and the interval(s) where it is decreasing. $$ g(x)=x \sqrt{x+1} $$
5 step solution
Problem 35
Find the absolute maximum value and the absolute minimum value, if any, of each function. $$ f(x)=e^{-x^{2}} \text { on }[-1,1] $$
4 step solution
Problem 35
Use the information summarized in the table to sketch the graph of \(f\). \(f(x)=\frac{4 x-4}{x^{2}}\) Domain: \((-\infty, 0) \cup(0, \infty)\) Intercept: \(x\) -intercept: 1 Asymptotes: \(x\) -axis and \(y\) -axis Intervals where \(f\) is \(\nearrow\) and \(\searrow: \nearrow\) on \((0,2)\); \(\searrow\) on \((-\infty, 0) \cup(2, \infty)\) Relative extrema: Rel. max. at \((2,1)\) Concavity: Downward on \((-\infty, 0) \cup(0,3)\); upward on \((3, \infty)\) Point of inflection: \(\left(3, \frac{8}{9}\right)\)
6 step solution
Problem 35
Determine where the function is concave upward and where it is concave downward. $$ f(x)=\frac{1}{x-2} $$
4 step solution
Problem 35
Find the interval(s) where the function is increasing and the interval(s) where it is decreasing. $$ f(x)=x^{2} e^{-x} $$
3 step solution
Problem 36
Find the absolute maximum value and the absolute minimum value, if any, of each function. $$ h(x)=e^{x^{2}-4} \text { on }[-2,2] $$
4 step solution
Problem 36
Use the information summarized in the table to sketch the graph of \(f\). \(f(x)=x-3 x^{1 / 3}\) Domain: \((-\infty, \infty)\) Intercepts: \(x\) -intercepts: \(\pm 3 \sqrt{3}, 0\) Asymptotes: None Intervals where \(f\) is \(\nearrow\) and \(\searrow: \nearrow\) on \((-\infty,-1) \cup(1, \infty) ;\) \(\searrow\) on \((-1,1)\) Relative extrema: Rel. max. at \((-1,2) ;\) rel. min. at \((1,-2)\) Concavity: Downward on \((-\infty, 0)\); upward on \((0, \infty)\) Point of inflection: \((0,0)\)
7 step solution
Problem 36
Determine where the function is concave upward and where it is concave downward. $$ g(x)=\frac{x}{x+1} $$
4 step solution
Problem 36
Find the interval(s) where the function is increasing and the interval(s) where it is decreasing. $$ f(x)=e^{-x^{2} / 2} $$
4 step solution
Problem 37
Find the absolute maximum value and the absolute minimum value, if any, of each function. $$ g(x)=(2 x-1) e^{-x} \text { on }[0,4] $$
4 step solution
Problem 37
Sketch the graph of the function, using the curve-sketching quide of this section. $$ g(x)=4-3 x-2 x^{3} $$
5 step solution
Problem 37
Determine where the function is concave upward and where it is concave downward. $$ f(x)=\frac{1}{2+x^{2}} $$
5 step solution
Problem 37
Find the interval(s) where the function is increasing and the interval(s) where it is decreasing. $$ f(x)=\frac{\ln x}{x} $$
3 step solution
Problem 38
Find the absolute maximum value and the absolute minimum value, if any, of each function. $$ f(x)=x e^{-x^{2}} \text { on }[0,2] $$
3 step solution
Problem 38
Sketch the graph of the function, using the curve-sketching quide of this section. $$ f(x)=x^{2}-2 x+3 $$
4 step solution
Problem 38
Determine where the function is concave upward and where it is concave downward. $$ g(x)=\frac{x}{1+x^{2}} $$
5 step solution
Problem 38
Find the interval(s) where the function is increasing and the interval(s) where it is decreasing. $$ f(x)=\ln x^{2} $$
4 step solution
Problem 39
Find the absolute maximum value and the absolute minimum value, if any, of each function. $$ f(x)=x-\ln x \text { on }\left[\frac{1}{2}, 3\right] $$
5 step solution
Problem 39
Sketch the graph of the function, using the curve-sketching quide of this section. $$ h(x)=x^{3}-3 x+1 $$
7 step solution
Problem 39
Determine where the function is concave upward and where it is concave downward. $$ h(t)=\frac{t^{2}}{t-1} $$
5 step solution
Problem 39
Find the interval(s) where the function is increasing and the interval(s) where it is decreasing. $$ f(x)=\frac{x^{2}-1}{x} $$
3 step solution
Problem 40
Find the absolute maximum value and the absolute minimum value, if any, of each function. $$ g(x)=\frac{x}{\ln x} \text { on }[2,5] $$
4 step solution
Problem 40
Sketch the graph of the function, using the curve-sketching quide of this section. $$ f(x)=2 x^{3}+1 $$
5 step solution
Problem 40
Determine where the function is concave upward and where it is concave downward. $$ f(x)=\frac{x+1}{x-1} $$
4 step solution
Problem 40
Find the interval(s) where the function is increasing and the interval(s) where it is decreasing. $$ h(x)=\frac{x^{2}}{x-1} $$
5 step solution
Problem 41
A stone is thrown straight up from the roof of an \(80-\mathrm{ft}\) building. The height (in feet) of the stone at any time \(t\) (in seconds), measured from the ground, is given by $$ h(t)=-16 t^{2}+64 t+80 $$ What is the maximum height the stone reaches?
5 step solution
Problem 41
Sketch the graph of the function, using the curve-sketching quide of this section. $$ f(x)=-2 x^{3}+3 x^{2}+12 x+2 $$
6 step solution
Problem 41
Determine where the function is concave upward and where it is concave downward. $$ g(x)=x+\frac{1}{x^{2}} $$
4 step solution
Problem 42
Lynbrook West, an apartment complex, has 100 two-bedroom units. The monthly profit (in dollars) realized from renting out \(x\) apartments is given by $$ P(x)=-10 x^{2}+1760 x-50,000 $$ To maximize the monthly rental profit, how many units should be rented out? What is the maximum monthly profit realizable?
5 step solution
Problem 42
Sketch the graph of the function, using the curve-sketching quide of this section. $$ f(t)=2 t^{3}-15 t^{2}+36 t-20 $$
5 step solution
Problem 42
Determine where the function is concave upward and where it is concave downward. $$ h(r)=-\frac{1}{(r-2)^{2}} $$
4 step solution
Problem 43
Sketch the graph of the function, using the curve-sketching quide of this section. $$ h(x)=\frac{3}{2} x^{4}-2 x^{3}-6 x^{2}+8 $$
4 step solution
Problem 43
Determine where the function is concave upward and where it is concave downward. $$ g(t)=(2 t-4)^{1 / 3} $$
3 step solution
Problem 44
The altitude (in feet) attained by a model rocket \(t\) sec into flight is given by the function $$ h(t)=-\frac{1}{3} t^{3}+4 t^{2}+20 t+2 \quad(t \geq 0) $$ Find the maximum altitude attained by the rocket.
4 step solution
Problem 44
Sketch the graph of the function, using the curve-sketching quide of this section. $$ f(t)=3 t^{4}+4 t^{3} $$
3 step solution
Problem 44
Determine where the function is concave upward and where it is concave downward. $$ f(x)=(x-2)^{2 / 3} $$
4 step solution
Problem 45
Data show that the number of nonfarm, full-time, self-employed women can be approximated by $$ N(t)=0.81 t-1.14 \sqrt{t}+1.53 \quad(0 \leq t \leq 6) $$ where \(N(t)\) is measured in millions and \(t\) is measured in 5 -yr intervals, with \(t=0\) corresponding to the beginning of 1963\. Determine the absolute extrema of the function \(N\) on the interval \([0,6]\). Interpret your results.
5 step solution
Problem 45
Sketch the graph of the function, using the curve-sketching quide of this section. $$ f(t)=\sqrt{t^{2}-4} $$
5 step solution
Problem 45
Determine where the function is concave upward and where it is concave downward. $$ f(x)=\frac{e^{x}-e^{-x}}{2} $$
4 step solution
Problem 46
AvERAGE SPEED OF A VEHICLE The average speed of a vehicle on a stretch of Route 134 between 6 a.m. and 10 a.m. on a typical weekday is approximated by the function $$ f(t)=20 t-40 \sqrt{t}+50 \quad(0 \leq t \leq 4) $$ where \(f(t)\) is measured in miles per hour and \(t\) is measured in hours, with \(t=0\) corresponding to 6 a.m. At what time of the morning commute is the traffic moving at the slowest rate? What is the average speed of a vehicle at that time?
7 step solution
Problem 46
Sketch the graph of the function, using the curve-sketching quide of this section. $$ f(x)=\sqrt{x^{2}+5} $$
4 step solution
Problem 46
Determine where the function is concave upward and where it is concave downward. $$ f(x)=x e^{x} $$
6 step solution
Problem 47
The management of Trappee and Sons, producers of the famous TexaPep hot sauce, estimate that their profit (in dollars) from the daily production and sale of \(x\) cases (each case consisting of 24 bottles) of the hot sauce is given by $$ P(x)=-0.000002 x^{3}+6 x-400 $$ What is the largest possible profit Trappee can make in 1 day?
5 step solution
Problem 47
Sketch the graph of the function, using the curve-sketching quide of this section. $$ g(x)=\frac{1}{2} x-\sqrt{x} $$
4 step solution
Problem 47
Determine where the function is concave upward and where it is concave downward. $$ f(x)=x^{2}+\ln x^{2} $$
4 step solution
Problem 48
The quantity demanded each month of the Walter Serkin recording of Beethoven's Moonlight Sonata, manufactured by Phonola Record Industries, is related to the price/compact disc. The equation $$ p=-0.00042 x+6 \quad(0 \leq x \leq 12,000) $$ where \(p\) denotes the unit price in dollars and \(x\) is the number of discs demanded, relates the demand to the price. The total monthly cost (in dollars) for pressing and packaging \(x\) copies of this classical recording is given by $$ C(x)=600+2 x-0.00002 x^{2} \quad(0 \leq x \leq 20,000) $$ To maximize its profits, how many copies should Phonola produce each month? Hint: The revenue is \(R(x)=p x\), and the profit is \(P(x)=\) \(R(x)-C(x)\).
5 step solution
Problem 48
Sketch the graph of the function, using the curve-sketching quide of this section. $$ f(x)=\sqrt[3]{x^{2}} $$
5 step solution
Problem 48
Determine where the function is concave upward and where it is concave downward. $$ f(x)=\frac{\ln x}{x} $$
5 step solution