Applications Of Derivatives Question 343

Question: If $ f(x)=x+\frac{1}{x}, $ x > 0, then its greatest value is

[RPET 2002]

Options:

A) - 2

B) 0

C) 3

D) None of these

Show Answer

Answer:

Correct Answer: D

Solution:

$ f(x)=x+\frac{1}{x} $

therefore $ {f}’(x)=1-\frac{1}{x^{2}} $

Put $ {f}’(x)=0 $ , $ x=-1,,1 $

Since x > 0, so no maximum value can be found.