CAT Exam Model Paper 7 with solutions for free online practice

${\mathit{x}}^4+16$ is always greater than ${\mathit{x}}^4$ and ${\mathit{x}}^2$ is always greater than ${\mathit{x}}^2-4$. Hence, yfx* will always be greater than ${\mathit{x}}^2-4$. So$\sqrt{\left({\mathit{x}}^4+16\right)}$is greater than ${\mathit{x}}^2-4$.
So the given two expressions can never be equal for any real value of x.