critical f(x)=-3x^4-24x^2+4y^3-12y-20

解答

临界点

f (x) = - 3 x^{4} - 24 x^{2} + 4 y^{3} - 12 y - 20

(0, 1), (0, - 1)

求解步骤

- 3 x^{4} - 24 x^{2} + 4 y^{3} - 12 y - 20

找到

\nabla f (x, y)

等于零或无定义的点

(0, 1), (0, - 1)

cr i t i c a l f (y) = 5 (9650 - y^{2}) - 19 y

cr i t i c a l x^{2} - 7 x + 2

cr i t i c a l x^{2} + y

cr i t i c a l f (x) = 5 x^{2} - 4 x

cr i t i c a l 2 x^{3} - x^{3} + \frac{x ^{4}}{4}