C2 Polynomial Question

Hi, i am trying to comprehend a C2 polynomial question where they have given me an equation and are asking me to factorise.

The question reads "Factorise 2x3 + x2 - 18x - 9"

According to the book, i am supposed to sub in -1, 1, 2 ,3 until i find f(p) = 0 so that i can successfully find the factor to the equation.

My question is, is this trial and improvement method the quickest way of finding what the factor is?

Thank you!!

Reply 1

SamKeene

Original post by JamesNeedHelp2

My question is, is this trial and improvement method the quickest way of finding what the factor is?

Thank you!!

Mostly, yes. Sometimes by looking at the coefficients you can figure out quickly if 1 or -1 would work. Maybe even with +-2. But with higher integers you really need to do the calculations.

Reply 2

JamesNeedHelp2

Original post by SamKeene

Mostly, yes. Sometimes by looking at the coefficients you can figure out quickly if 1 or -1 would work. Maybe even with +-2. But with higher integers you really need to do the calculations.