Classify the number $(\sqrt{2}-2{)}^2$ as "Rational" or "Irrational".

Classify $2\pi$ as Rational Number or Irrational Number.

Classify $\frac{1}{\sqrt{3}}$ as Rational Number or Irrational Number.

In the equation $y^2=16$, state whether variable $y$ represents "Rational Number" or "Irrational Number".

In the given equation, find whether variables $\mathrm{x}, \mathrm{y}, \mathrm{z}$ etc. represent rational or irrational numbers

$u^2=\frac{17}{4}$

In the given equation, find whether variables $x, y, z$ etc. represent rational or irrational numbers

$t^4=256$

On rationalising the denominator $\frac{1}{3+\sqrt{2}}$ we get $\frac{3-\sqrt{2}}{k}$. Find the value of $k$.

On rationalising the denominator $\frac{1}{\sqrt{7}-\sqrt{6}}$ we get $\sqrt{7}+\sqrt{k}$. Find the value of $k$.