Let f(x,y)=(x+y) 2
+e xy
Calculate ∂x
∂f
​
, ∂y
∂f
​
∂y∂x
∂ 2
f
​
and ∂x∂y
∂ 2
f
​
. b) Determine the gradient ∇f at the point (0,1). c) Find and classify the critical points of the function g(x,y)=x 3
+y 4
−3x+4y+6.