I was reading the last answer by Wyatt Kuehster in this Stack Exchange question.
There he uses the inequality:
$$\frac{|f(x)-f(x_0)|}{|\sqrt{f(x)}+\sqrt{f(x_0)}|}\leq |f(x)-f(x_0)|$$
It seems to me that this inequality is incorrect as the denominator can be less than 1.
For eg: let $f(x)=0.09$ and $f(x_0)=0.04$. Then denominator $=0.5$.
Then why is the inequality used in that answer? The answer got two upvotes. Or am I missing anything?