factorise polynomial x^3+x^2-4x-4 by long division method
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x^3 + x^2 -4x -4
let's take x= -1
(-1)^3 + (-1)^2 -4 (-1) -4
= -1 +1 +4 -4
=0
Therefore x+1 is a factor of the polynomial.
By long division, when we divide the polynomial by x+1, the quotient is x^2 - 4
Now we will factorize x^2 -4 using the identity a^2- b^2 = (a +b) (a -b)
x^2 -4 =( x+ 4) (x -4)
so the factors are (x+1) (x+4) and (x-4).
let's take x= -1
(-1)^3 + (-1)^2 -4 (-1) -4
= -1 +1 +4 -4
=0
Therefore x+1 is a factor of the polynomial.
By long division, when we divide the polynomial by x+1, the quotient is x^2 - 4
Now we will factorize x^2 -4 using the identity a^2- b^2 = (a +b) (a -b)
x^2 -4 =( x+ 4) (x -4)
so the factors are (x+1) (x+4) and (x-4).
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