8. Find all critical points for the function f(x,y) = zy + ë¦ + ë¦ and classify each as a local minimum, a local maximum, or a saddle point. Ans. Local minimum at (1,1) 9. Use Lagrange multiplier to find the extreme values of the function f(x, y)y, subject to the constraint z2 + y 1. Ans. Mazimum $, Minimum -1