Hello! I have a question about a problem I am trying to work out. The question asks to find the directional derivative of f(x,y,z)=x^2+yz at the point (1,-3,2) in the direction of the path r(t)=t^2i + 3tj+(1-t^2)k. Ok, first do I find the derivative of r(t) to get 3j +t(2i-2k) and then use 2i-2k as the direction vector to find the unit vector? Then the unit vector would be 1/sqrt (2i-2k) and then find the scalar product of the unit vector with the gradient of the f function? my final answer was 5*sqrt. Did I work this out right? I am studying for an exam and that is one of the problems I think will be on it. Thanks!