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I have tried using ti-89, ti-nspire and wolfram alpha, but none have given me a plot of this complex polynomial. I admit that I have may not inputted the formula correctly in wolfram alpha.

The polynomial:

$$ x^2 -ix+3$$ where $i$ is $\sqrt{-1}$.

El Santi
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    For any real number, your polynomial has a complex value, so what are you exactly expecting to get as a plot? – servabat Jan 12 '15 at 10:43
  • @servabat so there is no method of plotting this? – El Santi Jan 12 '15 at 11:03
  • @ElSanti, This is not the point. You should contextualize your problem. In some applications (e.g. Signal processing), we can plot the phase or the absolute value of complex functions to extract some signal information. So, it depends on you want. – Alex Silva Jan 12 '15 at 11:23
  • It totally depends on what you are willing to get. You must now that a complex number as a real and an imaginary part, so you can't just plot y as an x function (as you need 3 dimensions : one for the 'input' value and 2 for the complex number representation) – servabat Jan 12 '15 at 11:45
  • On WA, use $z$ instead of $x$ for plotting function in a single complex number. e.g. plot z^2 - i*z + 3 gives you this ( Two group of plots (3D/contour) for real and imaginary parts ). – achille hui Jan 12 '15 at 11:50

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You can use domain coloring:

enter image description here

The two roots can be seen clearly: they are the points having a rainbow around it.

lhf
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