does anybody have the answers to 12.8 webassign # 4 and 6? it's due at 10 tonight.

thanks

11/17/2006 7:46:35 PM

You should have posted the question - I've forgotten everything from Calc 3 but I'm sure someone else could have helped you.

11/17/2006 10:16:00 PM

yea...well it was late and i didn't have time...i was posting at work. times up now, thanks though

11/17/2006 10:54:16 PM

cheater

11/20/2006 12:24:52 AM

ok...i've got another 242 question...#4 on webassgn 13.3 it asks to find a function f such that FV = f. the equation is F(x,y) = (ye^xy + 4x^3*y)i + (xe^xy + x^4)j

F(x,y)= ?


i think I have the right answer, but struggling to get webassign to take it.

thanks

11/29/2006 7:06:17 PM

I'm not going to give you the answer, but post what you got, and I'll tell you whether or not it's right.

11/29/2006 7:14:28 PM

i have x*exp(xy)+x^4+(x^2*y^3*exp(xy))/2 i'm not so sure where i got the divided by 2 part, but I also tried x*exp(xy)+x^4

thanks for you help

11/29/2006 7:17:36 PM

No, that's not right.

(ye^xy + 4x^3*y) is the partial of f with respect to x, and (xe^xy + x^4) is the partial of f w.r.t. y.

Here's one way to do this problem:

1) Integrate (ye^xy + 4x^3*y) w.r.t. x, and add on some unknown function g(y), because such a function would have been lost in taking the partial w.r.t. x.
2) Integrate (xe^xy + x^4) w.r.t. y, and add on h(x).
3) The results of (1) and (2) should represent the same function f, so compare them to figure out what g(y) and h(x) are, and you get the answer.

11/29/2006 7:28:48 PM

thanks

11/29/2006 7:31:01 PM