Evaluate the following integrals:
∫ {1 + tan x tan (x + θ)} dx
tan(A - B) =
∴ tan(x - (x + θ )) =
∴ tan(θ) =
⇒ tan(θ)(1 + tanx.tan(x + θ )) = tan(x) - tan(x + θ)
⇒ (1 + tanx.tan(x + θ )) =
⇒