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