Man this one is a world of its own :D Just a quick question are you a fellow Add Math student in O levels i remember this question from back in the day :D Anyhow Lets get started
For this question we need to know the following identities:
Lets solve the bottom most part first:
Take LCM
now break the LCM
because 1/tan = cot x
and furthermore,
now we solve the above part and replace the bottom most part that we solved with