Hi,

Please help me solve these.

Thank you.

1. Find the four second partial derivatives of f(x, y) = xe' - sin(x/ y) +xy'. 2. Let z= f(x,y) where x=rcos0, y=rsin0. Show that Oz Oz Oz + Ox Or3. Find the minimum of f(x, y) = x + y +z subject to the constraint x+3y -2z =12. 4. Evaluate the following Iterated integrals. A. [[ (9 -x )dydx B. [[ xe dydx.5. Evaluate [[ (x - xy)dxdy; S is the region between y = x and y =3x-x. 6. Evaluate the volume of the solid bounded by the surface z = 9- x - y and the plane z = 0