Send questions of potential general interest to math21a@fas.harvard.edu.

 Question:Are we expected to know 1. derivatives/antiderivatives of inverse trig functions? 2. derivatives/antiderivatives of secant, cosecant, and cotangent? 3. double angle identities? Answer: 1. derivatives and anti derivatives of inverse trig functions need not to be memorized. An exception maybe is arctan'(x) = 1/(1+x^2) which is one of the integrals good to know. 2. One can live well without cot,csc,sec and consider only tan,sin,cos. 3. Double angle identities sin(2x) = 2 sin(x) cos(x), cos(2x)=cos^2(x)-sin^2(x) should be in everybody's backback. They are often useful. Question: I forgot to section for this course. Answer: Write Oliver (knill@math.harvard.edu) over the weekend and provide preferences which section suits you: MWF 9,10,11,12 or TTh 10-11:30, 11:30 to 1. Question: Does the international version of the book work? Answer: Yes, it is equivalent and usually a bit cheaper. In general, you might get a good deal also from buying a used book. Question: What is the difference between math21a and applied math21a? Answer: The syllabus of applied math21a has fluctuated in the past but theoretically, the material should be similar and you should get the same credit. Here are some differences: 1. math21a has smaller classes which is good for learning and allows you to have closer contact to teachers. 2. We use a computer algebra system and encourage the use of technology. 3. Having a large team working on the course gives you access to many resources. You can go to any office hours. 4. Math21a provides a math question center. 5. Math21a was stable over a decade (Oliver teaches it here since 11 years) and runs smoothly. Question: Is math21a suitable for math concentrators? Answer: Aspiring mathematicians should also consider math23, math25 or math55, where proofs are important. math21a has had a many math and applied concentrators in the past. Math21a covers all the standard multivariable calculus you ever need and has more applications than any other multivariable calculus course at Harvard. Look at previous exhibits. While some of our homework is applied, we refrain mostly from referring to knowledge from other sciences during exams to provide crystal clear problems. You find some old exam problems here when Oliver was teaching the Fall 2009 course or for the shorter summer course of summer 2011.