You can put this solution on YOUR website! I use Wolfram Alpha, which is a free, no-download computing engine similar to that of Wolfram Mathematica software.
http://www.wolframalpha.com/
You can type in something like "solve x^3 + 6x + 4 = 0" and it will find all zeros. Or, you could search other things, for example, the GDP of Belarus, or the fraction of people in the U.S. named "John."
