trig:

Syntax:	acos ( A )

	asin ( A )

	atan ( A )

	atan2 ( X , Y )

	cos ( A )

	cosh ( A )

	sin ( A )

	sinh ( A )

	tan ( A )

	tanh ( A )

Description:

	RLaB trigonometric functions are designed to take scalars, and
	matrices as arguments. The return value is the input argument
	with the trigonometric operation performed element by element.

	atan2() takes two arguments, which are the y, and x values
	used to form the tangent. All the trigonometric functions use
	the C language math library functions, so details about the
	ranges and error conditions can be found by examining the
	appropriate man pages on your system.

	Atan2 does not operate on complex arguments.

