Domain of the function

$$f(x)=\frac{1}{\sqrt{\left[x^2\right]-[x]-6}},$$

where $$[x]$$ is greatest integer $$\leq x$$ is

Let $$f:[2, \infty) \rightarrow R$$ be the function defined $$f(x)=x^2-4 x+5$$, then the ranges of $$f$$ is

$$f: R \rightarrow R$$ and $$g:[0, \infty) \rightarrow R$$ is defined by $$f(x)=x^2$$ and $$g(x)=\sqrt{x}$$. Which one of the following is not true?

If $$|3 x-5| \leq 2$$ then