Sponsored by the Rutgers University Department of Mathematics and the

Center for Discrete Mathematics and Theoretical Computer Science (DIMACS)

**Co-organizers:****Andrew Baxter**, Rutgers University, baxter{at} math [dot] rutgers [dot] edu**Doron Zeilberger**, Rutgers University, zeilberg {at} math [dot] rutgers [dot] edu

Title: Combinatorial Trigonometry

Speaker: **Doron Zeilberger**, Rutgers University

Date: Thursday, January 28, 2010 5:00pm

Location: Hill Center, Room 705, Rutgers University, Busch Campus, Piscataway, NJ

Abstract:

In Richard Stanley's wonderful talk (slide 8), that was recently given as the second of the three Colloquium talks at the 2010 annual joint mathematics meeting, he coined the term combinatorial trigonometry. I will expand the theme, and show that sine and cosine (and secant and tangent) are not what you think, but are, in fact, exponential generating functions enumerating combinatorial objects, and proving trig identities, so dreaded by billions of high school students, could actually be fun!