(a) $\int_{a}^{b}{\frac{|x|}{x}dx = \int_{a}^{0}\frac{|x|}{x}dx + \int_{0}^{b}\frac{|x|}{x}dx\ \ \ \lbrack\because a < 0 < b\rbrack}$ $= \int_{a}^{0}{- 1\ dx + \int_{0}^{b}{1\ dx}}$ $= a + b = b - ( - a)|b| - |a|$
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.