a.b = (1,sin^2(x)).(2,sin2x)= 2+sin2x(sinx)^2|a|^2 = 1+ (sinx)^4|b|^2 = 4+(sin2x)^2|a.b|=|a||b|=> (2+sin2x(sinx)^2)^2 = (1+ (sinx)^4)(4+(sin2x)^2) 4+4sin2x(sinx)^2+ (sin2x)^2.(sinx)^4 = 4+ (sin2x)^2+(...