(d) $\lim_{x \rightarrow 0}\frac{\left( 1 - \cos{2x} \right)}{x^{2}}$ $= \lim_{x \rightarrow 0}\frac{2\sin^{2}x}{x^{2}}$ $= 2\lim_{x \rightarrow 0}{\left( \frac{\sin x}{x^{2}} \right)^{2} = 2}$
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.