find-the-max-and-min-value-f-x-y-z-x-3-y-3-z-3-9xy-9xz-27x-

Question Number 182797 by universe last updated on 14/Dec/22

find the \max and \min value

f (x, y, z) = x^{3} + y^{3} + z^{3} - 9 xy - 9 xz + 27 x

Commented by mahdipoor last updated on 14/Dec/22

\pm \infty

g e t x = y = z \Rightarrow f = 3 x^{3} - 18 x^{2} + 27 x

m i n a n d m a x f = \pm \infty