Posted by Soroban on September 30, 2002 at 00:16:13:
In Reply to: polynomial /rational functions posted by helpimblonde on September 29, 2002 at 21:21:42:
: ok i have a test in 2 days!!! my teacher is terrible i cant understand this crap from her please help me.....
: FIND THE COMPLEX ZEROS OF THE POLYNOMIAL FUNCTION....how??
I'm sure you're aware of this rule:
if x = a is a root, then (x - a) is a factor.
Since f(-1) = 0, then (x + 1) is a factor of f(x).
So, f(x) = (x + 1)(x^3 + 2x^2 - 8).
But I can't find any roots for the cubic... sorry!
: ok one more...
: solve the equation in the complex number system:
This one factors nicely; (x^2 - 1)(x^2 + 9) = 0
So, the roots are: 1, -1, 3i, -3i
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