SOLUTION: Determine whether the following numbers are zero of the polynomial equation. P(x)=x^3-2x^2+4x-8 A). -2 B). 2i

Algebra ->  College  -> Linear Algebra -> SOLUTION: Determine whether the following numbers are zero of the polynomial equation. P(x)=x^3-2x^2+4x-8 A). -2 B). 2i      Log On


   



Question 1075280: Determine whether the following numbers are zero of the polynomial equation.
P(x)=x^3-2x^2+4x-8
A). -2
B). 2i

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
I would substitute the numbers or graph for the real numbers
for -2: -8-8-8-8 does not equal 0, so not a root
2i: 8i^3-8i^2+8i-8=-8i+8+8i-8 does work.
+2 is a root, so (x-2) is a factor
the other factor is (x^2+4)
The roots are 2, 2i, and -2i
For the purposes of this question, B.
graph%28300%2C300%2C-10%2C10%2C-10%2C10%2Cx%5E3-2x%5E2%2B4x-8%29