How do I simplify this equation so it equals to 3sin^2(x)?

Question

4+tan^2(x)-sec^2(x)/csc^2(x)

Answer 1

4+tan^2(x)-sec^2(x)/csc^2(x) = 4 + Sin^2(x)/Cos^2(x) - (1 / Cos^2(x)) / (1 / Sin^2(x))

= 4 + Sin^2(x)/Cos^2(x) - Sin^2(x)/Cos^2(x)

= 4

So you can't