18.1002/18.100B Real Analysis
Fall 2016
Instructor: David Jerison
TAs: Borys Kadets, Dmitrii Kubrak
Lecture: MWF2 (2-190)
Announcements
Final exam scores posted; final grade cutoffs
I am very happy with the overall performance on the final exam. The class median was 145/180 (one point over 80 percent). The final grades are awarded as follows: A > 82 percent, B >67 percent), C >52 percent(with + and - grades near the borderlines). Extra credit was added after the
cutoffs were computed so as to avoid influence.
Thanks for being such a good class. Have a very nice IAP
break.
Your questions were excellent: If any of you have more questions,
about your exam or about analysis in general, I invite you to visit
me any time.
The one final exam problem that everyone had trouble with
was showing that the second term, the constant c_2 in the
asymptotics of the sum n^{-\alpha} exists. The only mechanism to
show that it exists is to show that it is represented by a
convergent series, for example, a series of positive terms that is
bounded above. We did not have time to practice with asymptotic
expansions. In the second problem, with integration by parts,
many of you realized that an entire second integration by parts is
needed to establish that the first term is present. In the sum
n^{-\alpha}
problem, many of you found the O(1) bound and mistakenly
thought
that this finishes the argument. This also led several of you to
think you had computed c_2 when you did not have the correct value
for it.
With best wishes,
David Jerison
Announced on 26 December 2016 4:03 p.m. by David Jerison
Muddy answers 15 posted
I answered a few questions about the exam on the last muddy card post. Notably, in the list of proofs 1, you should aim at the most direct proof that is as self-contained as possible. You are responsible for the practice problems for the hour tests, although the ones specifically prepared forthe final should be your highest priority. There's a misprint in the
Arzela-Ascoli theorem, it should be part of problem 8 so it's clear that K is compact (and we are using 8b that C(K) is complete, not 6b which does not exist).
Announced on 20 December 2016 11:15 p.m. by David Jerison
Corrections to asymptotics notes posted
differentiate with respect to \alpha correctly. The corrected answers make the formulas a bit simpler. In 3a, at some
point I wrote N \ge M when I meant N \le M. These misprints are now fixed on a corrected version.
Announced on 20 December 2016 3:51 p.m. by David Jerison
Office hrs; new asymptotics posting
My office hrs for this week areMonday 6:30-8pm
Tues 1:30-3:30pm
Wed 1:30-3:30pm
I just posted notes on the asymptotics part of the final lecture along with the answers to the three practice exercises 1a, 2a and 3a and a few other related questions. I will answer muddy questions about exam problems in a later posting. I don't generally answer any direct questions of this type
in office hrs, except if they are (or will be) posted for the whole class.
Announced on 18 December 2016 8:48 p.m. by David Jerison
solutions to Exercise 0 (PS9 and PS11) just posted
discussion of asymptotics and a other commentary to follow late on Sunday.Announced on 16 December 2016 10:11 p.m. by David Jerison