Lecture 12 Slides
Merge pull request #166 from jayfo/lecture12

Lecture 12 Slides
Lecture 12 Slides Fix
Merge pull request #167 from jayfo/lecture12fix

Lecture 12 Slides Fix
Rearranging content for 3c.
Merge pull request #168 from depstein/3c

Rearranging content for 3c.