critical f(x)=4-2x^3-2y^3+24x+6y

解答

临界点

f (x) = 4 - 2 x^{3} - 2 y^{3} + 24 x + 6 y

(- 2, 1), (- 2, - 1), (2, 1), (2, - 1)

求解步骤

4 - 2 x^{3} - 2 y^{3} + 24 x + 6 y

找到

\nabla f (x, y)

等于零或无定义的点

(- 2, 1), (- 2, - 1), (2, 1), (2, - 1)

cr i t i c a l f (x) = 3 x^{2} y + y^{3} - 3 x^{2} - 3 y^{2} + 2

cr i t i c a l f (x) = (ln (x))^{2}

cr i t i c a l f (x) = \frac{x ^{2}}{( x - 1 )}

\frac{d}{d x} (\frac{2 x y}{x ^{2} + 2 y ^{2}})

cr i t i c a l y = \frac{x ^{2} - 4}{x ^{2} + 4}