Question

If $x+\frac{1}{x}=3$, then $x^2+\frac{1}{x^2}$ will be.

• A. $9$
• B. $10$
• C. $27$
• D. $7$

Answer 1

Answer: (D)

$7$

$x+\frac{1}{x}=3$

Squaring both side

$\Rightarrow (x{)}^2+(\frac{1}{x}{)}^2+2\times x\times \frac{1}{x}=9$

$\Rightarrow x^2+\frac{1}{x^2}+2=9$

$\therefore x^2+\frac{1}{x^2}=7$.