spacewacko
New Member
USA
2 Posts 
Posted  10/08/2007 : 20:26:53

Find direction in which the directional derivative of the function f(x,y)=xy + y^2 at point (1,1) is maximum?
I'm trying to use:gradient vector dot vector u=mag. of gradient mag.u cos .
I found the partials of x and y based on that I pluged in my point to get the gradient vector <1,3>. For my u vector I used <cos ,sin>.For the magnititude I got <1,3>= 10 and for <cos ,sin>=1. 
Edited by  spacewacko on 10/08/2007 20:45:58 

