I've seen harder (limits of converging sequences, etc), but wolfram alpha made them harder for humans than for automated scripts. My captcha was to find the l

I've seen harder (limits of converging sequences, etc), but wolfram alpha made them harder for humans than for automated scripts. My captcha was to find the least zero of this polynomial: http://random.irb.hr/latexrender/pictures/c46ad0f30d7575c609d863329f5e59f7.gif http://random.irb.hr/latexrender/pictures/c46ad0f30d7575c609... and all I had to do was to OCR the formula: http://www.wolframalpha.com/input/?i=x^3+%2B+3x^2-4x+-12+%3D%3D+0 http://www.wolframalpha.com/input/?i=x^3+%2B+3x^2-4x+-12+%3D...