Question

cot x cot 2y-cot 2xcot3x-cot3x cotx=1 . prove it .
and why we take solution of this question cot3x=cot(2x+x) and evalute this only ..and not solve cotx cot 2y-cot 2xcot3x-cot 3xcot x
if u understand my question please answer correctly and perfectly.
I will mark u as brainlist ​

Answer 1

Answer:

please refer to the attached file