website that solves complex cubic, quartic, and quadratic functions [closed]

Is there a website that helps solve complex, quartic, and quadratic functions. For example, if we were given the following function:

ax^3+bx^2+cx+d=0


It would solve it for you?

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Offtopic, but... WolframAlpha? – darij grinberg Jan 18 2012 at 19:55
Well, if you found one that solves quintics, that would be in topic for this site. – Federico Poloni Jan 18 2012 at 20:57
I decree today that life is simply taking and not giving, England is mine, it owes me a living – Yemon Choi Jan 18 2012 at 22:09
I recommend euler's elements of algebra for the clearest possible explanation of solution of a cubic assuming only the solution of a quadratic. archive.org/details/elementsalgebra00lagrgoog – roy smith Jan 21 2012 at 20:58