## Colloquium: “What do trigonometry and combinatorics have to do with each other?”

Marshall University Math Colloquium

February 4, 2015

Elizabeth Niese

*Marshall University*

**Abstract**

Combinatorics is the study of how to count. Results from the field of combinatorics are used in probability and statistics, computer science, physics, and elsewhere. Trigonometry is the study of triangles and how their angles relate to side lengths. At first glance, these two topics seem quite unrelated. In this talk we will look at how some common trigonometric functions encode the number of up-down permutations.