please solve any of these or both please:2*1)2sin(two sin square)y+4cos(x+y)sin(x)sin(y)+cos2(x+y)=a)cos 2xb)cos2yc)sin2xd)sin2y*2) and very useful trignomentry tips and easy ways.

Hii Hemanth Question 1 is not clear bro.. use ^ for power.. like sin to the power 2 = sin^2(x) sin^2(x+y) + cos^2(x+y) + cos2(x+y) then it will be clear which is 2x which is square x. For second question (2) In any chapter of Mathematics...you must do as much practice as u can to make it stronger. There is book named as "Objective Approach in Mathematics" by Amit M Agrawal In vol 1 ..Trignometry is given..In this book all class of problems are given..so you can solve it.. And After solving atleast 200 question in trignometry you will have good command on it..so do as much practice as you can....Practice will give you your own tips and ways.. After solving 50 question from arihant...do the previous year jee question...you will see you can solve all of them... WIth regards Yagya askiitians_expert