(a) ${\lim_{n \rightarrow \infty}\left( 1 + \sin\frac{a}{n} \right)}^{n} = e^{\lim_{n \rightarrow \infty}\frac{\sin{a/n}}{a/n.\ \frac{1}{a}}} = e^{a}$
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.