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