(a) Let $I = \int_{}^{}{\frac{(x^{3} + 3x^{2} + 3x + 1)}{(x + 1)^{5}}\ dx}$ $= \int_{}^{}\frac{(x + 1)^{3}}{(x + 1)^{5}}dx = \int_{}^{}\frac{1}{(x + 1)^{2}}\ dx$ $= - \frac{1}{(x + 1)} + c$
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.