SOLUTION: What are all the zeros of f(x)=x^3-x^2-7 x+3

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: What are all the zeros of f(x)=x^3-x^2-7 x+3      Log On


   

Question 952383: What are all the zeros of f(x)=x^3-x^2-7 x+3
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
What are all the zeros of f(x)=x^3-x^2-7 x+3
use the rational roots theorem with synthetic division:
...0...|.....1......-1.....-7.......3
...1...|.....1.......0.....-7......-4(real root between 0 and 1)(change in sign of last number)
...2...|.....1.......1.....-5......-7
...3...|.....1.......2.....-1.......0 (3 is a root)
f(x)=(x-3)(x^2+2x-1)
zeros are 3 plus two irrational roots