differentiability

Consider the function $$f\left( x \right) = \left| x \right|$$ in the interval $$\,\, - 1 \le x \le 1.\,\,\,$$ At the point $$x=0, f(x)$$ is

The function $$y = \left| {2 - 3x} \right|$$

If a function is continuous at a point its first derivative