SIGN IN SIGN UP

Merge pull request #9 from Yeeler/master

fix a matrix typo in section 3.6 in week 1
H
Huang Haiguang committed
8900a2ccbf55732be859894e99ffdc77e8f97123
Committed by GitHub <noreply@github.com> on 4/26/2018, 2:28:27 PM