Concept:Convert the integral to a function of tanx using the substitution t=tanx, then apply partial fractions and standard integration formulas.Explanation:Let t=tanx.Then dx=1+t2dt and sin2x=1+t2t2.So the denominator becomes:sin2x+tan2x=1+t2t2+t2=1+t2t2(1+t2)+t2=1+t2t2(t2+2).Thus the integral simplifies to:∫sin2x+tan2xdx=∫t2(t2+2)dt.Using partial fractions:t2(t2+2)1=21(t21−t2+21).Integrating term by term:21∫t2dt−21∫t2+2dt=−2t1−221tan−1(2t)+C.Substitute back t=tanx:∫sin2x+tan2xdx=−2tanx1−221tan−1(2tanx)+C.Answer:Option B: 2tanx−1−221tan−1(2tanx)+c