Question

Use the gradient to find the directional derivative of the function at P in the direction of Q.
f(x,y)=sin(2x)cosy,P(pi,0),Q(pi/2,pi)

Answer 1

I would just like someone to check to see if I've gotten the PQ vector and unit vectors correct so far

Answer 2

For vector PQ I get pi/2i-pij

Answer 3

sorry <- pi/2,-pi>