For a positive definite diagonal matrix $A$, I want to prove that for any $x$: $$\frac{x^T \sqrt{A} x}{\|\sqrt{A}x\|_2} > \frac{x^T A x}{\|Ax\|_2}$$ So far I cannot find any counterexamples, and it intuitively makes sense since the $\sqrt{\cdot}$ operator should bring the eigenvalues of $A$ closer to $1$, but I can't prove this.