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