f(x) =

- Addition (x+y)
- Subtraction (x-y)
- Multiplication (x*y or (x)(y))
- Division (x/y)
- Exponents (x^y or x^(1/y) for roots)
- The following functions: sin, cos, tan, asin, acos, atan, abs
- Single variable evaluation (include "x" in the expression string)