x^4-4x^3+3x^2+8x-16
Find the zeroes given one is x^2-x-4.
I don't know what to do now. i tried synthetic division. pls help : D
x^4-4x^3+3x^2+8x-16
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x^2 - x - 4
= x^2 - 3 x + 4 by long division
x = [3 +/- sqrt (9-16) ]/2
[3 +/- i sqrt (7)]/2
for the second pair of complex roots
for the original 2 roots
x = [ 1 +/- sqrt(1+16)]/2