The set `S_(1)` and `S_(2)` are solution sets of `(1+a)cos theta cos (2 thetacos (2 theta-b)=(1+a cos 2 theta)cos (theta-b)`

Options

A. `{n pi , n in Z}` and `1/2 {n pi +(-1)^(n)sin^(-1)(a sin b)=b , n in Z}`
B. `{n (pi)/2, n in Z}` and `{ n pi+(-1)^(n)sin^(-1)(a sin b ), n in Z}`
C. `{n (pi)/2, nin Z}` and `{n pi +(-1)^(n)sin^(-1)(a/2 sin b), nin Z}`
D. None of these

Answer

A