Show that $u=\sum_{k=0}^\infty k^{-2} \delta_{1/k}$ is a distribution, but ...

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Show that $u=\sum_{k=0}^\infty k^{-2} \delta_{1/k}$ is a distribution, but $v=\sum_{k=0}^\infty \frac{1}{k} \delta_{1/k}$ is NOT a distribution. Then find the support of u.

The definition of $$|T(\psi)| \leq C_N \sum_{|\alpha| \leq N} ||\partial^\alpha \psi||_\infty$$.

So what I have so far is

$$|<T_u,\psi>=|\int_{-\infty}^\infty \sum_{k=0}^\infty \frac{1}{k^2}\delta_{1/k}\psi(k)dk|$$

Is this the right starting point?

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I'm not entirely sure what your work is supposed to convey. One thing to note is that you should never associate delta distributions to integration in this way. It is not a function. Do not treat it as such.

Note that if $f\in C_c^{\infty}(\mathbb{R})$, then $\langle u,f\rangle = \sum_{k=1}^{\infty} \frac{1}{k^2}f\left(\frac{1}{k}\right)$. You know that $f$ is bounded so this supplies the proof.

To see that $v$ is not a distribution, take $f$ to be $1$ on $[-2,2]$. What could you say about $\langle v,f\rangle$ in this case?