Solution:
The provided function is $f(x)=2 x^{2}-1$
Now we will check continuity at $x=3$
$\lim _{x \rightarrow 3} f(x)=\lim _{x \rightarrow 3}\left(2 x^{2}-1\right)$
$=2(3)^{2}-1=17$
And $f(3)=2(3)^{2}-1=17$
As a result, $\lim _{x \rightarrow 3} f(x)=f(x)$ therefore $\mathrm{f}(\mathrm{x})$ is continuous at $\mathrm{x}=3$.