# Question #28428

##### 1 Answer

Aug 5, 2017

#### Explanation:

Let

First, to find factors I would try to solve:

for small values of

E.g.

If

Unfortunately, no values of

So, can we factorise the cubic part in brackets further?

Well, if we graph the cubic part, you can see that there is only one x-intercept, which means that the cubic function can't be factorised any further (more factors means more x-intercepts).

graph{x^3+2x^2+x-1 [-10, 10, -5, 5]}

So because the cubic part can't be factorised, taking out