The first midterm had an average score of 76, with a standard deviation 15.
Errata:
 Practice exam 3: TF problem 18 was labeled incorrectly. It is false as the explanation tells. (Thanks to Aukosh)
 Practice exam 3: TF problem 16 was labeled wrong because it was not z=g(x,y). It is not a good problem.
If you have z = g(x,y), then the parametrization is r(u,v) = (u,v,g(u,v)). The problem is now changed. (Thanks for the
alert by Aukosh).
 Practice exam 1: sotution to one matching problem was not complete (Thanks to Chinmay Paranjape).
 Practice exam 2: 4) solution was missing, 6d) used wrong data. Improvements: parametrization of torus uses 2+sin(phi).
(Thanks to Wenying Huang).
 Practice exam 3: Problem 10 uses point (5,0,2) not (5,2,0)
(Thanks to Wenying Huang).
