Find the absolute extrema of the function $$f(x,y)=2xy-x-y$$ over the region of the $xy$-plane bounded by the parabola $y=x^2$ and the line $y=4.$
I was wondering if I needed to use Lagrange multipliers to solve this problem and if I do, how would I go about solving this problem? If someone could help me, that would be great! Thanks