prove that sin18.cos36=1/4

 Solution:- 

How to Prove:-

• To prove sin18.cos36=1/4 we have to take L.H.S that is sin18.cos36

• At the next step we have to put the value of sin18 and cos36 that's are root5-1/4 and root5+1/4 respectively.

• Now solving it properly we got 4/16, on further solving we get the exact R.H.S that is 1/4

• Hence L.H.S=R.H.S