Question:
Mark (√) against the correct answer in the following:
If $f\left(x+\frac{1}{x}\right)=x^{2}+\frac{1}{x^{2}}$ then $f(x)=?$
A. $x^{2}$
B. $\left(x^{2}-1\right)$
C. $\left(x^{2}-2\right)$
D. None of these
Solution:
$f\left(x+\frac{1}{x}\right)=x^{2}+\frac{1}{x^{2}}=\left(x+\frac{1}{x}\right)^{2}-2$
$\Rightarrow \mathrm{f}(\mathrm{x})=\mathrm{x}^{2}-2$