$f\left(x\right)=\left|x\right|$ is differentiable at $x=0$.

The area bounded by the curves $y=\left|x-1\right|+\left|x-2\right|$ and $y=3$ is equal to

Let $f:R\to R$ be defined by $f\left(x\right)=\left\{\begin{array}{lll}2x& ;x>3& \\ x^2& ;1<x\le 3& \\ 3x& ;x\le 1& \end{array}\right.$ 

Then $f\left(-1\right)+f\left(2\right)+f\left(4\right)$ is