Question

If $x^2+\frac{1}{x^2}=7$, then the values of $x+\frac{1}{x}$ is

• A. 2
• B. 3
• C. 5
• D. 6

Answer 1

Answer: (B)

3

Given, $x^2+\frac{1}{x^2}=7$
Since, $(x+\frac{1}{x}{)}^2=x^2+\frac{1}{x^2}+2.x.\frac{1}{x}$
$=x^2+\frac{1}{x^2}+2$
$=7+2$
$=9$
$\therefore x+\frac{1}{x}=3$.
Option B is correct.