The correct option is D None of these
Let I=∫3π10π5cosxcosx+sinxdx
Multiply numerator and denominator by sec3(x)
I=∫3π10π5sec2xsec2x+sec2xtanxdx=∫3π10π5sec2x1+tanx+tan2x+tan3xdx
Put t=tanx⇒dt=sec2xdx
∴I=∫tan3π10tanπ51u2+u3+u+1du=∫3π10tanπ5(1−u2(u2+1)+12(u+1))du
=12∫tan3π10tanπ5(1u2+1−uu2+1)du+12∫tan3π10tanπ5u+1du
=[−14log(u2+1)+12log(u+1)+12tan−1u]log3π10logπ5=π20