(a) If

f(x, y) = log(x + y) + sin(xy) + y^2e^x, determine partial df/dx and partial df/dt

find df/dt in terms of

x and y where x = cos t, y = sin t using the chain rule formula. [ 10 marks ]

(b) If f(x, y) = x3 − y2 − xy, determine partial df/dx and p-artial df/dy

If f = 0 then express dy/dx in terms of x and y. Just a quick answer check for a i got: df/dt=(1/x+y+ycos(xy)+y^2e^x)*-y+(1/x+y+ycos(xy)+y^2e^x)*x Now im sure this isnt in the simpliest form For part b i got dy/dx= (-3x^2+y)/(-2y-x)? Many thanks in advance.