What is the extreme f(x)=3x+9/x ?

The extreme f(x)=3x+9/x is Maximum(-sqrt(3),-6sqrt(3)),Minimum(sqrt(3),6sqrt(3))

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

extreme f(x)=3x+9/x

extreme

Maximum (- 3, - 63), Minimum (3, 63)

Solution steps

f^{'} (x) = 3 - \frac{9}{x ^{2}}

Find intervals:

Increasing

: - \infty < x < - 3,

Decreasing

: - 3 < x < 0,

Decreasing

: 0 < x < 3,

Increasing

: 3 < x < \infty

Plug

x = - 3

into

3 x + \frac{9}{x} : - 63

Maximum (- 3, - 63)

Plug

x = 3

into

3 x + \frac{9}{x} : 63

Minimum (3, 63)

Maximum (- 3, - 63), Minimum (3, 63)

What is the extreme f(x)=3x+9/x ?
The extreme f(x)=3x+9/x is Maximum(-sqrt(3),-6sqrt(3)),Minimum(sqrt(3),6sqrt(3))