extreme f(x)=2x^2-36ln(x)

解答

极值点

f (x) = 2 x^{2} - 36 ln (x)

极小值 (3, 18 - 36 ln (3))

求解步骤

f^{'} (x) = 4 x - \frac{36}{x}

Find intervals:

递减

: 0 < x < 3,

递增

: 3 < x < \infty

将

x = 3

代入

2 x^{2} - 36 ln (x) : 18 - 36 ln (3)

极小值 (3, 18 - 36 ln (3))

e x t re m e y = x^{2} - 8 x + 12

e x t re m e f (x, y) = x^{3} + x y^{2} + 6 x y

e x t re m e f (x, y) = 4 x y - 2 x^{4} - y^{2} + 4 x - 2 y

e x t re m e f (x) = 5 (x - 3)^{2} (2 x + 1) (x + 4)^{3}

e x t re m e f (x y) = - x^{2} - y^{2} + 22 x + 18 y - 102