∫sin x / x = ∫(1 - (x2/3!) + (x4/5!) - (x6/7!) + ....)dx We know that, ∫xndx = x(n+1)/n+1 + C where, C is the integration constant Thus, ∫sin x / x = x - (x3/3×3!) + (x5/5×5!) - (x7/7×7! ) + ....+ C Hence, the expression on integrating sin x/ x is x - (x3/3×3!) + (x5/5×5!) - (x7/7×7! ) + ....+ C