Use Lagrange multipliers to find the maximum and minimum values of the function subject to the given constraint. f(x, y) = 7x²+7y²; xy = 1

We need to optimize f(x,y) = 7x² + 7y² subject to the constraint g(x, y) = xy = 1. To find the possible extreme value points, we must use Vf = XVg.
We have Vf =