I am having a hard time doing the following problems. First off all the notation is confusing the hell out of me. This is the first time i have used this notation so it is making learning very difficult. Here are my questions. Prove the following function is differentiable, and find the derivative at an arbitarary point. 1.) f:R2-->R,(x,y)|--> exy 2.) let f(u,v,w) = (eu-w, cos(v+u) + sin(u+v+w)) and g(x,y) = (ex, cos(y-x), e-y). Calculate fog and D(fog)(0,0). Thanks.