Q. If $f(x) = |x - 2| + |x + 1| - x,then\ f^{'}( - 10)$ is equal to
A) $- 3$
B) $- 2$
C) $- 1$
D) 0
Explanation
(a)
For $x < - 1$
$f(x) = - (x - 2) - (x + 1) - x = - 3x + 1$
$\therefore\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ f^{'}(x) = - 3$
$\Rightarrow \ \ \ \ \ \ \ \ \ f^{'}( - 10) = - 3$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.