1. In a worksheet, type the name of the function to define.
2. Type a left parenthesis. A placeholder and the closing parenthesis appear.
3. In the placeholder, type a list of arguments, separated by commas. The arguments must be names. They cannot be more complicated expressions.
4. Insert the definition operator, :=. A second placeholder appears.
5. In the placeholder, type an expression or a string. Variables on the right must be either previously defined or be part of the argument list. Undefined variables are circled in red.
Additional Information
• When you reassign function names, you need not specify the list of arguments. sin1 := sin.
• To check if a name is assigned to a built-in function, type it in and press =. If it is a built-in function, a message appears. If it is not, an error message appears.