greetings . i have two questions regarding the sinc function in the week limit , where it can be used as a nascent delta function. the definition :

$\lim_{\varepsilon \rightarrow 0}\frac{1}{\pi }\int_{-\infty}^{\infty}dx\frac{sin\left(\frac{x-x_{0}}{\varepsilon}\right) }{x-x_{0}} \phi(x)=\phi(x_{0})$

is said to be valid for any smooth function $\phi(x)$ with compact support . does that mean that the following is not valid :

$ \lim_{\varepsilon \rightarrow 0}\frac{1}{\pi }\int_{-\infty}^{\infty}dx\frac{sin\left(\frac{x-x_{0}}{\varepsilon}\right) }{x-x_{0}}x=x_{0} $

moreover . if we expand the sine function, we get :

$\lim_{\varepsilon \rightarrow 0}\frac{1}{\pi }\int_{-\infty}^{\infty}\phi(x)\sum_{n=0}^{\infty}\frac{(-1)^n(x-x_{0})^{2n}}{(2n+1)!(\varepsilon)^{2n+1}}dx =\lim_{\varepsilon \rightarrow 0}\frac{1}{\pi}\sum_{n=0}^{\infty}\frac{(-1)^{n}}{(2n+1)!(\varepsilon )^{2n+1}} \int_{-\infty}^{\infty}(x-x_{0})^{2n}\phi(x) dx =\phi(x_{0}) $

is it legit to perform the integration term by term ??