If \(\left \lfloor \right \rfloor\) denotes the greatest integer function, then find the value of \(\displaystyle\lim_{x\rightarrow0}\dfrac{\tan (\left \lfloor -2\pi^2\right \rfloor x^2)-x^2\tan (\left \lfloor -2\pi^2\right \rfloor)}{\sin^2 x}\)
1
20
2
-20 + tan 20
3
20 + tan 20
4
tan 20