f(x) =
Addition+(x+y)
Subtraction-(x-y)
Multiptdcation*(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)