∫cos2x−cos2θcosx−cosθdx is equal to
2(sinx+xcosθ)+C
2(sinx-xcosθ)+C
2(sinx+2xcosθ)+C
2(sinx−2xcosθ)+C
∫cos2x−cos2θcosx−cosθdθ=∫2cos2x−1−2cos2θ−1cosx−cosθdθ
=2∫cos2x−cos2θcosx−cosθdθ=2∫(cosx+cosθ)dθ=2sinx+2xcosθ+C