Maple commands and functions use types, and a specific number or order of arguments. If you do not use the correct type or argument, an error is generated.

Solution 1

Use the type or whattype command to verify the type of argument.

Solution 2

Use the Describe command or review the related help page to see correct usage. In this case, review the calling sequence for cos

 in the trig help page.

 Describe, type, whattype