Problem:Find the absolute maximum and minimum values for f(x,y) = sin x + cos y on the rectangle R defined by 0<=x<=2pi and 0<=y<=2pi using the method of Lagrange Multipliers.

I'm having trouble putting the constraints into something I can work with.

I know gradient[f(x,y)] = lambda1*gradient[g1] + lambda2*gradient[g2], but what are my g1 and g2 functions? Thanks