extreme f(x)=2x^2+8y^2

解答

极值点

f (x) = 2 x^{2} + 8 y^{2}

极小值 (0, 0)

求解步骤

找到临界点:

(0, 0)

\frac{\partial ^{2} f}{\partial x ^{2}} = 16

D (x, y) = 64

检查在每个临界点处的符号

检查临界点

(0, 0) :

极小值

极小值 (0, 0)

e x t re m e f (x) = 3 x^{5} - 25 x^{3} + 60 x + 1

e x t re m e f (x) = - 7 x^{2} - 5 y^{2} + 14 x + 10 y - 2

e x t re m e x^{4} + 8 x^{3} - 14 x^{2}

e x t re m e f (x) = 5 x^{2} - 30 x, 0 \leq x \leq 5

e x t re m e x \cdot e^{- x^{2}}