F(x)=4x+8/x решите уравнения f'(x)=0

Question

F(x)=4x+8/x решите уравнения f'(x)=0

Answer 1

F'(x) = 4 - 8/x^2
4 - 8/x^2 = 0
4 = 8/x^2
4x^2 = 8
x^2 = 2
x = +sqrt(2)         x = -sqrt(2)

Answer 2

F'(x) = 4 - 8/x^2
4 - 8/x^2 = 0
4 = 8/x^2
4x^2 = 8
x^2 = 2
x =корень из2 x = корень из -2