For the last part of the STEP Question I tried the following - please excuse the basic formatting
(1 + sin 2θ)/(1+cos 2θ) = (cos²θ + sin²θ + 2sinθ cosθ)/(2cos²θ)
which, if you take good care of the stray ½, you can basically rewrite as
((sinθ + cos θ)/(cos θ))²
Remembering that this lives inside a ln (), from here I used the laws of logs and the first part of the question.
Is this a valid approach?