I need some help with these questions. Thank you so much for your help in advance

1) Find the absolute minimum and maximum value for the function f(x,y) =xy+x3+2x2 on the region

R = [ (x,y) : -2 x 2, 0 y 4x2 ]

2) Use Lagrange multipliers to find the extreme values of the function f(x,y) =exy subject to the constraintx3+y3=16

3) Find the value ofDuf(1,1) for u =<101,103 and f (x,y) =x2sin(y4)+xy