Final embarrassing corrections to the notes

I'm in office today, and have talked to four of you ... and got two errors pointed out. In case you intend to bring those notes for the exam, you might want to update. 

Recent updates (i.e. May, two of these updates have been announced here): 

• Today: the convexity/concavity lecture note, page 14. Drawing was correct.
• Today: the quasiconcavity lecture note, page 6. Formulae were correct.
  • I also put a note down the lower-right corner, but that is not a correction. 
• May 15: The solution note to the 2018 exam got its second correction in a few days. 
• May 14: The solution note to the 2017 exam had a number corrected for problem 2.

A final admonishment, and good luck.