4 ms·
This was pretty cool. Once on an exam in a differential equations class, the instructor made a mistake in the problem that required integrating sec(x). This is
by Bo102010 15y ago
This was pretty cool. Once on an exam in a differential equations class, the instructor made a mistake in the problem that required integrating sec(x).
This is a fairly difficult integral, since it requires the trick of multiplying by 1 in a clever way. http://math2.org/math/integrals/more/sec.htm http://math2.org/math/integrals/more/sec.htm
- nilaykumar 15y agoHaha, yeah. That one's pretty cool too. There are a couple of slightly more easier-to-see ways, but they still involve seemingly arbitrary multiplications of cosine, etc (or product-to-sum rules). Man... integrals. Love/hate relationship.
- btilly 15y agoIn my first Calculus course I had failed to memorize some trig integral, and rederived it on the spot. Unfortunately what I came up with differed from the usual by some complex trigonometric substitution. The grader saw a ton of work, not the usual answer, and didn't bother differentiating it to demonstrate that it was correct, and marked me wrong. I was ticked off about that for some time. (Wouldn't have changed my grade, but it was the principle of the thing.)