It is said that $$ \mathcal{M}(\text{SL}_2(\mathbb{Z}))=\mathbb{C}[E_4,E_6] $$
where $\mathcal{M}(\text{SL}_2(\mathbb{Z}))$ is the graded ring of module forms over $\text{SL}_2(\mathbb{Z})$ and $E_4,E_6$ are normalized Eisenstein series.
I'm new to modular form and not quite familiar about the Eisenstein series so I fail to prove it.
Any one give some ideas?

