If $f$ continuous at $x\_0$ and $f(x\_0)>0$ 

then how to show there exist $\epsilon>0$ and $\delta>0$ such that $f(x)>0$ for $|x-x\_0|<\delta$.

I don't know to start proving and then i use definition continuous function at $x\_0$ is

$\forall\epsilon>0, \, \exists\delta>0 \, \text{such that if }|x-x\_0|<\delta\implies |f(x)-f(x\_0)|<\epsilon$