Epsilon delta limit definition [closed]

Let $f\colon\Bbb R\to\Bbb R$ be defined as$$f(x)=\begin{cases}\frac1{x^2},&x\neq0\\0,&x=0\end{cases}$$

Prove $f$ is continuous at any $c\neq0$ by using $\varepsilon-\delta$ definition of limit of function.