sin^2 x + cos^2 x = 1
using that, derive what the cot^2 x would equal to.
would it be
csc^2 x - 1 = cot^2 x
given: sin^2 x + cos^2 x = 1
divide each term by sin^2 x
1 + cos^2 x / sin^2 x = 1/sin^2 x
1 + cot^2 x = csc^2 x
which reduces to your answer.
Good job