Competition Calculus Problems and Techniques

[n1person]

I am currently signed up for the Harvard-MIT Math Tournament for Algebra and Calculus (an example: http://web.mit.edu/hmmt/www/datafiles/solutions/2009/solutions-calculus-2009.pdf). I am able to solve a fair number, but some of the solutions are just completely incomprehensible (see the last problem). I've taken BC Calculus, Multivariable Calculus, Linear Algebra, and Differential Equations and studied little bits of Analysis, but I was curious if anyone knew of a good online source of problems and/or techniques to solve these sorts of difficult single-variable calculus problems (use of techniques like variation of parameters (see last problem: http://web.mit.edu/hmmt/www/datafiles/solutions/2007/scalc07.pdf) or use of Catalan numbers to solve sums, etc). Thanks for your help!

 

[n1person]

here is a new question, seeing how people don't seem to like my old one:

Does anyone know of schools other than U of North Texas which holds integration bees or similar events, particularly those that might post the questions and/or solutions online?