Factorising Cubic Polynomial

To factorise cubic polynomial p(x), we

• Find x = a where p(a) = 0
• Then (x – a) is the factor of p(x)
• Now divide p(x) by (x – a) i.e. (p(x))/((x - a))
• And then we factorise the quotient by splitting the middle term

Let us take an example

In Example 15 ,

1. We first find x where p(x) = 0.
2. x = 1
3. So, (x – 1) is a factor of p(x)
4. We divide p(x) by (x – 1)
5. We get quotient g(x)
6. We factorise g(x) using splitting the middle term