I am having difficulty with this problem
Let R) be the region in the plane bounded by the coordinate-axes and the line x + 2y = 6 and let f(x,y) = x^2 - xy.
a) find the absolute max and min of f(x,yf) on R (NOTE: don't forget to look for optimal value ona ll the edges of the boundary)
b)Use part a) to find a lower bound as well as an upper bound for the double integral of f(x,y)dA
c)Evaluate the integral you found in part b and verify that its value actually does lie between the upper and lower bound of part b)