Slaughter a horde of pirates to get back to The_Ninja's_Solutions
Prove that $ *:L^{p}(\mathbb{R}^n)\times L^{q}(\mathbb{R}^n)\rightarrow C(\mathbb{R}^n) $ is well defined, if $ 1/p+1/q=1, 1\le p\le\infty $
Let $ \epsilon>0 $
$ \exists h \in C_{0}(\mathbb{R}^n) $ s.t. $ \left|\left|f-h\right|\right|_{p}<\epsilon $