SOLUTION: One root of the equation x^3+x^2-2=0 is 1. What are the other two roots? a. 1+/-2i b. -1+/-i c. +/-1+2i d. +/-1-i I used the root they gave and then did synthetic divi

Algebra ->  Rational-functions -> SOLUTION: One root of the equation x^3+x^2-2=0 is 1. What are the other two roots? a. 1+/-2i b. -1+/-i c. +/-1+2i d. +/-1-i I used the root they gave and then did synthetic divi      Log On


   

Question 986884: One root of the equation x^3+x^2-2=0 is 1. What are the other two roots?
a. 1+/-2i
b. -1+/-i
c. +/-1+2i
d. +/-1-i
I used the root they gave and then did synthetic division. But I got +/-i√2. What did I do wrong?
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


I suspect what you did was forget to put in a zero place holder for a missing term when you did your synthetic division. If you did:
  1  |  1   1   -2
            1    2
     --------------
        1   2    0

and then interpreted the result as , you would get the result you reported. Try this:

  1  |  1   1   0  -2
            1   2   2
     ----------------
        1   2   2   0

which result would be interpreted as . Let me know how that works for you.

John

My calculator said it, I believe it, that settles it