Limits Continuity And Differentiability

$f(x)$ is continuous $\forall \mathrm{x} \in \mathrm{R}$

$f(x)>0, \forall x>1$

$f(x)$ is not differentiable but continuous $\forall x \in \mathrm{R}$

$f(x)$ is not differentiable for two values of $x$