Question

Find all first partial derivatives:

f(x,y)=e^(xy)cosx

Answer 1

Fx = ye^(xy)cosx - e^(xy)sinx
= e^(xy) (ycosx - sinx)

Fy = xe^(xy) cosx

Answer 2

Find, f1(0,180°) if (x,y)= e^(xy)cos(x+y).

Answer 3

Find, f1(0,180°) if f(x,y)=e^(xy)cos(x+y)