Chapter 12

Applied Mathematics: For the Managerial, Life, and Social Sciences · 118 exercises

Problem 1

Find the critical point(s) of the function. Then use the second derivative test to classify the nature of each point, if possible. Finally, determine the relative extrema of the function. \(f(x, y)=1-2 x^{2}-3 y^{2}\)

4 step solution

Problem 1

Let \(f(x, y)=x^{2}+2 y^{2}\). a. Find \(f_{x}(2,1)\) and \(f_{y}(2,1)\). b. Interpret the numbers in part (a) as slopes. c. Interpret the numbers in part (a) as rates of change.

4 step solution

Problem 1

Let \(f(x, y)=2 x+3 y-4\). Compute \(f(0,0), f(1,0), f(0,1)\), \(f(1,2)\), and \(f(2,-1) .\)

5 step solution

Problem 2

Find the critical point(s) of the function. Then use the second derivative test to classify the nature of each point, if possible. Finally, determine the relative extrema of the function. \(f(x, y)=x^{2}-x y+y^{2}+1\)

5 step solution

Problem 2

Let \(f(x, y)=9-x^{2}+x y-2 y^{2}\). a. Find \(f_{x}(1,2)\) and \(f_{y}(1,2)\). b. Interpret the numbers in part (a) as slopes. c. Interpret the numbers in part (a) as rates of change.

4 step solution

Problem 2

Let \(g(x, y)=2 x^{2}-y^{2}\). Compute \(g(1,2), g(2,1), g(1,1)\), \(g(-1,1)\), and \(g(2,-1) .\)

3 step solution

Problem 3

Find the critical point(s) of the function. Then use the second derivative test to classify the nature of each point, if possible. Finally, determine the relative extrema of the function. \(f(x, y)=x^{2}-y^{2}-2 x+4 y+1\)

4 step solution

Problem 3

Find the first partial derivatives of the function. \(f(x, y)=2 x+3 y+5\)

3 step solution

Problem 3

Let \(f(x, y)=x^{2}+2 x y-x+3\). Compute \(f(1,2), f(2,1)\), \(f(-1,2)\), and \(f(2,-1)\).

5 step solution

Problem 4

Find the critical point(s) of the function. Then use the second derivative test to classify the nature of each point, if possible. Finally, determine the relative extrema of the function. \(f(x, y)=2 x^{2}+y^{2}-4 x+6 y+3\)

5 step solution

Problem 4

Find the first partial derivatives of the function. \(f(x, y)=2 x y\)

2 step solution

Problem 4

Let \(h(x, y)=(x+y) /(x-y) .\) Compute \(h(0,1), h(-1,1)\), \(h(2,1)\), and \(h(\pi,-\pi) .\)

8 step solution

Problem 5

Find the critical point(s) of the function. Then use the second derivative test to classify the nature of each point, if possible. Finally, determine the relative extrema of the function. \(f(x, y)=x^{2}+2 x y+2 y^{2}-4 x+8 y-1\)

5 step solution

Problem 5

Find the first partial derivatives of the function. \(g(x, y)=2 x^{2}+4 y+1\)

4 step solution

Problem 5

Let \(g(s, t)=3 s \sqrt{t}+t \sqrt{s}+2\). Compute \(g(1,2), g(2,1)\), \(g(0,4)\), and \(g(4,9)\)

4 step solution

Problem 6

Find the critical point(s) of the function. Then use the second derivative test to classify the nature of each point, if possible. Finally, determine the relative extrema of the function. \(f(x, y)=x^{2}-4 x y+2 y^{2}+4 x+8 y-1\)

5 step solution

Problem 6

Find the first partial derivatives of the function. \(f(x, y)=1+x^{2}+y^{2}\)

2 step solution

Problem 6

Let \(f(x, y)=x y e^{x^{2}+y^{2}}\). Compute \(f(0,0), f(0,1), f(1,1)\), and \(f(-1,-1)\)

6 step solution

Problem 7

Find the critical point(s) of the function. Then use the second derivative test to classify the nature of each point, if possible. Finally, determine the relative extrema of the function. \(f(x, y)=2 x^{3}+y^{2}-9 x^{2}-4 y+12 x-2\)

5 step solution

Problem 7

Find the first partial derivatives of the function. \(f(x, y)=\frac{2 y}{x^{2}}\)

3 step solution

Problem 7

Let \(h(s, t)=s \ln t-t \ln s\). Compute \(h(1, e), h(e, 1)\), and \(h(e, e)\)

6 step solution

Problem 8

Find the critical point(s) of the function. Then use the second derivative test to classify the nature of each point, if possible. Finally, determine the relative extrema of the function. \(f(x, y)=2 x^{3}+y^{2}-6 x^{2}-4 y+12 x-2\)

4 step solution

Problem 8

Find the first partial derivatives of the function. \(f(x, y)=\frac{x}{1+y}\)

4 step solution

Problem 9

Find the critical point(s) of the function. Then use the second derivative test to classify the nature of each point, if possible. Finally, determine the relative extrema of the function. \(f(x, y)=x^{3}+y^{2}-2 x y+7 x-8 y+4\)

5 step solution

Problem 9

Find the first partial derivatives of the function. \(g(u, v)=\frac{u-v}{u+v}\)

4 step solution

Problem 9

Let \(g(r, s, t)=r e^{s / t} .\) Compute \(g(1,1,1), g(1,0,1)\), and \(g(-1,-1,-1)\)

3 step solution

Problem 10

Find the critical point(s) of the function. Then use the second derivative test to classify the nature of each point, if possible. Finally, determine the relative extrema of the function. \(f(x, y)=2 y^{3}-3 y^{2}-12 y+2 x^{2}-6 x+2\)

5 step solution

Problem 10

Find the first partial derivatives of the function. \(f(x, y)=\frac{x^{2}-y^{2}}{x^{2}+y^{2}}\)

4 step solution

Problem 10

Let \(g(u, v, w)=\left(u e^{v w}+v e^{w w}+w e^{u t}\right) /\left(u^{2}+v^{2}+w^{2}\right)\). Compute \(g(1,2,3)\) and \(g(3,2,1)\).

3 step solution

Problem 11

Find the critical point(s) of the function. Then use the second derivative test to classify the nature of each point, if possible. Finally, determine the relative extrema of the function. \(f(x, y)=x^{3}-3 x y+y^{3}-2\)

5 step solution

Problem 11

Find the first partial derivatives of the function. \(f(s, t)=\left(s^{2}-s t+t^{2}\right)^{3}\)

4 step solution

Problem 11

Sketch the level curves of the function corresponding to each value of \(z\). . \(f(x, y)=2 x+3 y\)

4 step solution

Problem 12

Find the critical point(s) of the function. Then use the second derivative test to classify the nature of each point, if possible. Finally, determine the relative extrema of the function. \(f(x, y)=x^{3}-2 x y+y^{2}+5\)

5 step solution

Problem 12

Find the first partial derivatives of the function. \(g(s, t)=s^{2} t+s t^{-3}\)

2 step solution

Problem 13

Find the critical point(s) of the function. Then use the second derivative test to classify the nature of each point, if possible. Finally, determine the relative extrema of the function. \(f(x, y)=x y+\frac{4}{x}+\frac{2}{y}\)

4 step solution

Problem 13

Find the first partial derivatives of the function. \(f(x, y)=\left(x^{2}+y^{2}\right)^{2 / 3}\)

5 step solution

Problem 14

Find the first partial derivatives of the function. \(f(x, y)=x \sqrt{1+y^{2}}\)

4 step solution

Problem 14

Sketch the level curves of the function corresponding to each value of \(z\). \(f(s, t)=\sqrt{s^{2}+t^{2}}\)

4 step solution

Problem 15

Find the critical point(s) of the function. Then use the second derivative test to classify the nature of each point, if possible. Finally, determine the relative extrema of the function. \(f(x, y)=x^{2}-e^{y^{2}}\)

4 step solution

Problem 15

Find the first partial derivatives of the function. \(f(x, y)=e^{x y+1}\)

2 step solution

Problem 16

Find the critical point(s) of the function. Then use the second derivative test to classify the nature of each point, if possible. Finally, determine the relative extrema of the function. \(f(x, y)=e^{x^{2}-y^{2}}\)

6 step solution

Problem 16

Find the first partial derivatives of the function. \(f(x, y)=\left(e^{x}+e^{y}\right)^{5}\)

3 step solution

Problem 17

Find the critical point(s) of the function. Then use the second derivative test to classify the nature of each point, if possible. Finally, determine the relative extrema of the function. \(f(x, y)=e^{x^{2}+y^{2}}\)

5 step solution

Problem 17

Find the first partial derivatives of the function. \(f(x, y)=x \ln y+y \ln x\)

4 step solution

Problem 18

Find the first partial derivatives of the function. \(f(x, y)=x^{2} e^{y^{2}}\)

4 step solution

Problem 18

Sketch the level curves of the function corresponding to each value of \(z\). \(h(u, v)=\sqrt{4-u^{2}-v^{2}}\)

3 step solution

Problem 19

Find the critical point(s) of the function. Then use the second derivative test to classify the nature of each point, if possible. Finally, determine the relative extrema of the function. \(f(x, y)=\ln \left(1+x^{2}+y^{2}\right)\)

5 step solution

Problem 19

Sketch the level curves of the function corresponding to each value of \(z\). \(f(x, y)=2 x+3 y ; z=-2,-1,0,1,2\)

2 step solution

Problem 20

Find the critical point(s) of the function. Then use the second derivative test to classify the nature of each point, if possible. Finally, determine the relative extrema of the function. \(f(x, y)=x y+\ln x+2 y^{2}\)

6 step solution

Problem 20

Find the first partial derivatives of the function. \(f(x, y)=\frac{e^{x y}}{x+y}\)

3 step solution

Show/ page