Built-in functions are used to perform operations on expressions that are less common than the standard arithmetic operations like addition and multiplication. A call to a built-in function consists of the function identifier, followed by the expression enclosed in parentheses, like this:
sin(3 * x)
Use the Contents tab to see what built-in functions are available (under Writing formulas, Reference, Functions).
You can also declare and use your own functions. See Functions.
See Also
Operators