\\\text{(a) Find the maximum and minimum values of }f(x,y) = x-x^2+y^2\text{ on the rectangle }\\0 \leq x \leq 3, 0 \leq y \leq 2.\\\text{(b) Find the maximum and minimum values of }f(x,y) = xy(1-x-y)\text{ on the triangle with vertices (0,0), (2,0), (0,2).}