Question

using factor theorem factorise each of the following polynomial x³+ 2x² - x - 2​

Answer 1

To factorise the given cubic polynomial

Let p(x) represent the given polynomial

p(x)=x³+2x²-x-2

We know that,

Any polynomial is equal to zero

So,p(x)=0

→x³+2x²-x-2=0

→x²(x+2)-1(x+2)=0

→(x²-1)(x+2)=0

→(x²-1)(x+2)=0

→(x-1)(x+1)(x+2)=0

→x-1=0,x+1=0 and x+2=0

→x=1,-1 and 2

→x=±1 and 2