Question

The set of x-intercepts of the graph of f(x) = x^3 -2x^2 -x +2 is?

Answer 1

set f(x) to 0.
0=x^3-2x^2-x+2

by factoring out the right hand side, you get 0= (-2+x)(-1+x)(1+x), solve for x which matches the solution of 0.

Answer 2

Could you show me with steps how you factored the right hand side? thats what i had trouble with

Answer 3

use synthetic method.

Answer 4

Can you show me that?

Answer 5

read it, at the middle of the page. The first part is about long division, skip it.

Answer 6

http://www.purplemath.com/modules/synthdiv.htm

Answer 7

f(x) = x^3 -2x^2 -x +2
0 = x^3 - 2x^2 - x + 2
0 = x^2(x - 2) - 1(x - 2)
0 = (x - 2)(x^2 - 1)
0 = (x - 2)
0 = (x^2 - 1)

`2` = x
1 = x^2
`±1` = x