HELP!!! Simplify cos^2 0 -1/ 4sin^2 0?

We need to simpify the given expression. The given expression to us is ,
Given Expression :-
[tex]\sf\implies \dfrac{ cos^2\theta -1}{4 \ sin^2\theta }[/tex]
Using Identity :-
[tex]\sf\implies \red{ sin^2\theta + cos^2\theta = 1}[/tex]
So that :-
[tex]\sf\implies - sin^2\theta = cos^2\theta -1[/tex]
We have :-
[tex]\sf\implies \dfrac{ cos^2\theta -1}{4 \ sin^2\theta } \\\\\sf\implies\dfrac{ - sin^2\theta}{4sin^2\theta}=\boxed{\sf -\dfrac{1}{4}} [/tex]
Hence the required answer is -1/4.