We can write above integral as:

(Adding and subtracting 1 in numerator)

Consider

(∵ sin²x + cos²x = 1 and sin2x = 2 sinx.cosx)

--- (1)

[From (1)]

Considering,

(Adding and subtracting 1 in denominator)

--(2)

Putting values in (2) we get,

Substituting value of u we get,