Ye kya bawaseer hai!? ( T: wtf is this!? )

Kisi se hua hai ye wala. Meri to gamd haat mai aa gai, 15 minute gaye alag se. Cos(2x) wala substitute le raha tha par samajh nhi aay uske aage.

T: Did anybody attempt this one? This was a pain in the butt, wasted 15 minutes on one too. I did take the cos(2x) substitution but am blanking after that.

Set 1