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.
Describe the region R below using polar coordinates:

2<=r<=3
pi/2<=theta<=(3pi)/2
Evaluate the iterated integral:
int_0^1 int_0^y xe^(y^3) dx dy
1/6(e-1)
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
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
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.
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
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
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
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>>
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.
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
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
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
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
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
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
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
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)>>
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
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
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
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
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.