This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
Using Descarte's rule of signs, we see that x 3 − x − 1 has 1 sign change, therefore one real solution. Trying to solve via synthetic division gives a remainder, so we need another method to solve it. We rewrite the equation with an x-squared term: x 3 + 0 x 2 − x − 1 Since we cannot solve through factoring: x = 3 2 1 + ( 3 − 1 ) 3 + ( 2 1 ) 2 + 3 2 1 − ( 3 − 1 ) 3 + ( 2 1 ) 2 − ( 3 1 ) ⋅ 0 ≈ 1 . 6 5 Now we add: 2 . 6 5 1 + 1 + 0 1 + 1 + 0 1 ≈ 2 . 3 So we round down, and get a result of 2.