How many complex roots does the polynomial have?
This is correct; the polynomial can be factored as
The term accounts for the triple occurrence of the real root x=2. indeed has the four complex roots listed above.
My graphing calculator, the TI-85, gets it wrong: It comes up with only one real root x=2, the other six roots it lists are complex. Admittedly, two of the complex roots have a very tiny imaginary part (the number in front of the i), so they are "nearly" real.
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