First, let's recall one of the Reciprocal Identities. Note that we will need to rearrange the terms so that we can use it for our expression.
cot θ = 1/tan θ ⇔ 1/cot θ = tan θ
With this identity we can substitute 1cot θ for tan θ in our expression.
Now we will use one of the Pythagorean Identities.
1 + cot^2 θ = csc^2 θ
With this identity we can substitute csc^2 θ for 1 + cot^2 θ in our expression.
