Find the extremum of the implicit function z = Z (x, y) determined by the equation 2x ^ 2 + 2Y ^ 2 + Z ^ 2 + 8xz-z + 8 = 0

Find the extremum of the implicit function z = Z (x, y) determined by the equation 2x ^ 2 + 2Y ^ 2 + Z ^ 2 + 8xz-z + 8 = 0

2x^2+2y^2+z^2+8xz-z+8=0
Find the partial derivative of X, let z'x = 0. Get x = - 2Z
Find the partial derivative of X, let z'y = 0. Get y = 0
Substituting into the original formula, 7z & sup2; + Z-8 = 0, Z1 = 1 (maximum), Z2 = - 8 / 7 (minimum) are obtained