posted by Anonymous .
f(x) = x3 + 2x2 – 0.4X – 1
how do you you factor this?
Do not repost a question which has been answered.
Please use ^ before exponents.
There is no simpl standard formula for finding the roots of cubic equations. First create integer coefficients by rewriting as
(1/5) (5x^3 + 10x^2 -2x -5)
There are no simple factors with integers for this equation. That can be proven with something sometimes called the "p/q theorem". It can be faotored to
f(x) = 5[(x-0.689)(x+1.941,(x+0.748)]
I used an online solver for that.
The numbers in the factors are rounded.