<trigonometric_function> ::=
  COS ( <expression> )
| SIN ( <expression> )
| TAN ( <expression> )
| COT ( <expression> )
| COSH ( <expression> )
| SINH ( <expression> )
| TANH ( <expression> )
| ACOS ( <expression> )
| ASIN ( <expression> )
| ATAN ( <expression> )
| ATAN2 ( <expression>, <expression> )
| RADIANS ( <expression> )
| DEGREES ( <expression> )