Explanation

(d)
We have, $f(x) = |x|(x - 1)(x - 2)(x - 3)$
$= \left\{ \begin{array}{r}
x(x - 1)(x - 2)(x - 3),\ x \geq 0 \\
- x(x - 1)(x - 2)(x - 3),\ \ x < 0
\end{array} \right.\$
[image:6_image23.emf]
It is clear from the figure that, there are four critical points
$ie,\ 0,\ \alpha,\ \beta,\ \gamma\$