When you square a number, whether it's positive or negative, the square is always positive. That is, a2 is positive whether a is positive or negative. Examples:
12 = 1 x 1 = 1
(-1)2 = (-1) x (-1) = 1
52 = 5 x 5 = 25
(-5)2 = (-5) x (-5) = 25
Since the answer is always positive, you don't need the absolute value signs: |a2| = a2.

David W.
Assuming that y = Ia^2I if a<0 is one line of the definition for a STEP FUNCTION, there may be other lines for a=0 and for a>0, so the qualifier "if a<0" should remain on your answer: a^2 if a<006/03/21