Optimus Prime
The Pirate said "rdr matey"
Double the Trouble
I'm partial to the Giants
The Dodgers suck, but Calculus applications rock!
100

The local maximum and minimum values and saddle point(s) of the function 

f(x,y)=x^2+xy+y^2+y

f(1/3,-2/3) = -1/3

is a local minimum.

100

Describe the region R below using polar coordinates:

2<=r<=3

pi/2<=theta<=(3pi)/2

100

Evaluate the iterated integral:

int_0^1 int_0^y xe^(y^3) dx dy

1/6(e-1)

100

Find the first partial derivatives of the function

f(x,y)=x/y

f_x(x,y)=1/y

f_y(x,y)=-x/y^2

100

Find the equation of the tangent plane to the surface

z=e^(x-y)

at the point (2,2,1).

z=1+1(x-2)-1(y-2)

z=x-y+1

200

The local maximum and minimum values and saddle point(s) of the function 

f(x,y)=2-x^4+2x^2-y^2

(0,0,2) is a saddle point.

f(1,0) = 3 and f(-1,0) = 3 are local maxima.

200

Sketch the region whose area is given by the integral and evaluate the integral.

int_(pi/4)^((3pi)/4) int_1^2 r dr d theta 

200

Set up integrals for both orders of integration where

int int_D y^2 e^(xy) dA

and D is bounded by

y=x, y=4,x=0

int_0^4 int_x^4 y^2 e^(xy) dy dx

or

int_0^4 int_0^y y^2 e^(xy) dx dy

200

Find the first partial derivatives of the function

f(x,y,z)=x^3yz^2+2yz

f_x(x,y,z)=3x^2yz^2

f_y(x,y,z)=x^3z^2+2z

f_z(x,y,z)=2x^3yz+2y

200

Find the maximum rate of change of the function

f(x,y)=sin(xy)

at the point (1,0) and the direction in which it occurs.

The maximum rate of change is

|gradf(1,0)|=1

in the direction of 

gradf(1,0) = <<0,1>>

300

The marketing department of a company has determined that if it spends x thousands of dollars on radio advertisements and y thousands of dollars on newspaper advertisements, the company's revenue (in thousands of dollars) will be 

R(x,y)=-0.07x^2-100y^2+4x+5y+2xy

How much money should this company spend of radio advertisements and newspaper advertisements to maximize its revenue?

$33,750 on radio advertising and $362.50 on newspaper advertising will maximize revenue.

300

Set up the integral

int int_D x^2ydA

by changing to polar coordinates, where D is the top half of the disk with center origin and radius 5.

int_0^pi int_0^5 r^4 cos^2thetasinthetadrd theta

300

Evaluate the double integral

int int_D (x^2+2y)dA

, where D is bound by 

y=x,y=x^3, x>=0

23/84

300

If 

z=x^4+x^2y,

 x=s+2t-u,

y=stu^2

Find

(delz)/(dels)

when s = 4, t = 2, and u = 1 

1,582

300

Find the equation of the tangent plane to the surface

xy+yz+zx=5

at the point (1,2,1).

3(x-1)+2(y-2)+3(z-1)=0

3x+2y+3z=10

400

Use Lagrange multipliers to find teh extreme values of the function 

f(x,y,z)=2x+2y+z

subject to the constraint

x^2+y^2+z^2=9

The maximum value is f(2,2,1) = 9.

The minimum value is f(-2,-2,-1) = -9

400

Use polar coordinates set-up a double integral to find the volume of the solid that lies below the cone 

z=sqrt(x^2+y^2)

and above the ring 

1<=x^2+y^2<=4

int_o^(2pi) int_1^2 r^2 dr d theta

400

Sketch the region of integration and change the order of integration.

int_0^2 int_(x^2)^4 f(x,y) dy dx

int_0^4 int_0^sqrt(y) f(x,y) dx dy

400

Find the gradient of 

f(x,y,z)=y^2e^(xyz)

gradf(x,y,z)=<<y^3ze^(xyz),(xy^2z+2y)e^(xyz),xy^3e^(xyz)>>

500

Find the dimensions of a rectangular box of maximum volume such that the sum of the lengths of its 12 edges is 36 inches.

3 in x 3 in x 3 in

500

Convert the integral to polar coordinates:

int_0^3int_-sqrt(9-x^2)^sqrt(9-x^2)e^(x^2+y^2)dydx

int_(-pi/2)^(pi/2)int_0^3e^(r^2)r dr d theta

500

Find the volume of the solid that lies under the plane 

3x+2y-z=0

and above the region enclosed by the parabolas

y=x^2

and

x=y^2

3/4

500

Find the directional derivative of the function

g(u,v)=u^2e^-v

at the point (3,0) in the direction of the vector

vecv=<<3,4>>

-18/5

500

A manufacturer has modeled its yearly production function P (the value of its entire production, in millions of dollars) as a Cobb-Douglass function:

P(L,K)=1.47L^0.65K^0.35

where L is the number of labor hours (in thousands) and K is the invested capital (in millions of dollars).  Suppose that when L = 30 and K = 8, the labor force is decreasing at a rate of 2,000 labor hours per year, and capital is increasing at a rate of $500,000 per year.  Find the rate of change of production.

Production is decreasing at a rate of about $596,000 per year.

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