I've only just completed week 2 today and I hope to start week 3 tomorrow.
I've been using this page:
https://share.coursera.org/wiki/inde...stro:Equations for a nice list of the formula.
And yes, the homework has made me think. While I've made a number of mistakes, I've eventually got there. I hope it all sticks, but even if it doesn't I'll have (re)learned a lot.