Abs

Absolute value function. The absolute value of a negative number is equal to the number multiplied by (-1). The absolute value of a positive number is equal to the number itself.

Default parameter values:
	a = 1, b = 1, c = 0

Example:
	a = 1, b = 1, c = 0

	Input = - 5.3  =>  Output = 	5.3
	Input = 10.7  =>  Output = 	10.7