I agree with you, but not everything can be done pictorially. FWIW, an animation of the quadratic formula/completing the square: http://en.wikipedia.org/wiki/F

I agree with you, but not everything can be done pictorially. FWIW, an animation of the quadratic formula/completing the square: http://en.wikipedia.org/wiki/File:Completing_the_square.gif http://en.wikipedia.org/wiki/File:Completing_the_square.gif