Question

What is the smallest and the largest value of f(x,y)=-3x+y in X={(x,y)[is an element of] R^2: x>=0 and y>=0 and 1= 13 years ago

Answer 1

Right, so step 1: draw a diagram of the region.

Now, this function clearly doesn't have a local max or min in the interior of that region, as the partial derivatives of f are non-zero constants.

Hence, you need to look at each piece of the boundary.