extreme f(x)=(x-4)^2+(y-4)^2-4/(sqrt(5))

解答

极值点

f (x) = (x - 4)^{2} + (y - 4)^{2} - \frac{4}{5}

极小值 (4, 4)

求解步骤

找到临界点:

(4, 4)

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

D (x, y) = 4

检查在每个临界点处的符号

检查临界点

(4, 4) :

极小值

极小值 (4, 4)

e x t re m e 3 x^{4} + 7 x^{3} - 1 8^{2} - 32

e x t re m e f (x) = 0.2 x^{2} - 20 x + 900

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

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

e x t re m e f (x) = x^{3} + 5 x^{2} - 8 x + 1