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WorksheetsPartial Derivatives
Total questions: 10
Worksheet time: 15mins
Find the first order partial derivative with respect to y
f(x,y)=x3y2+3xey
.
fy(x,y)=3x2y2+3ey
fy(x,y)=3x2y2+2x3y+3ey+3xey
fy(x,y)=2x3y+3xey
fy(x,y)=6x2+3ey
The temperature at T at a location in the Northern Hemisphere depends on longitude x, latitude y, and time t, so we can write T=f(x,y,t). The time measured since January 1. What is the meaning of the partial derivatives dT/dx?
The rate of change of temperature with respect to time
The rate of change of temperature as longitude and time varies
The rate of change of temperature as longitude varies with latitude and time fixed
The rate of change of the time with respect to temperature
Find dy/dx by Implicit Differentiation
2xy3−x2y=2
2xy−2y3
x(6y2−x)2y(x−y2)
x−2y
2
Suppose at the point (1,2, f(1,2)), fxx(1,2)=−5 , fyy(1,2)=4 , and fxy(1,2)=−2 . Then at that point there is a:
Saddle point
Local Max
Local Min
Cannot be determined
When finding local extrema, suppose the D>0 and fxx<0 at a point. Then that point is:
A local max
A local min
A saddle point
Cannot be determined.
4yz3+3x2z2−xyexyzyzexyz−2xz3
4yz3+3x2z2−xyexyz2xz3−yzexyz
yzexyz−2xz34yz3+3x2z2−xyexyz
2xz3−yzexyzxyexyz−4yz3−3x2z2
Partial derivatives graphically is define as
A constant
The 2D slope of the slice of a 3d graph
The 3D derivative
The derivative of the whole thing
Which one of the following is always true?
fxy=fxx
fxy=fyx
fxx=fyy
fxy=fyy
f(x,y)=x3−2xy+3y2 Which of the following is true?
fx=3x2−2y+y3; fy=6x
fxx=6x; fxy=−2+3y2
fx=−2x+6y+3xy2;fy=3x2−2y+y3
fxx=6+6xy;fyy=6x
Find fx and fy from the equation f(x,y)= ln(x2y3)
fx=x1 fy=2y3
fx=xy1 fy=2y3x
fx=x1 fy=23x
fx=y3x2 fy=2y33x2
