Here are some of the math handouts I've written. Newer (and better!) handouts coming soon. In particular, a progective geometry and a symmetric polynomials handout are currently in progress.
Beside each handout, I've indicated a difficulty range based on AMC/AIME/JMO/USAMO difficulty. Recommended handouts have a star beside them.
*Power of a Point [Easy AIME - Mid USAMO]
*Invariants and Monovariants [Mid AIME - Easy USAMO]
Probability States [Hard AMC - Hard AIME]
Linearity of Expectation [Hard AMC - Hard AIME]
Vieta's Formulas [Easy AIME - Mid JMO]