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diff() function
11-09-2014, 02:29 PM
Post: #1
diff() function
A diff() problem:

Example: f(x,y):+x²-2*x*y+3*y²+2*x-2*y

1.) diff(f(x,y),x) ---> 2.*x-2.*y+2.
2.) diff(f(x,y),y) ---> -2*x+6*y-2

x - direction:
3.) diff(diff(f(x,y),x)) ---> 2
4.) diff( 2.*x-2.*y+2,x) ---> 2
5.) diff(f(x,y),x$2) ---> 2

y - direction:
6.) diff(diff(f(x,y),y)) ---> -2
7.) diff(-2*x+6*y-2,y) ---> 6
8.) diff(f(x,y),y$2) ---> 6

The second derivative in the x-direction worked properly.
The second derivative in the y-direction worked improperly in the red highlighted case(??)

(The template key entry method worked properly for these examples.)
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Messages In This Thread
diff() function - DrD - 11-09-2014 02:29 PM
RE: diff() function - Han - 11-09-2014, 02:51 PM
RE: diff() function - DrD - 11-09-2014, 05:53 PM



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