Please help in factorising this polynomial.
y = 2x^3 - x^2 - 8x + 4
also x + 2 is a factor
i used the remainder theorem and then long divided the equation
and i ended up with..
(x+2)(2x+1)(x-3)
help? lol
many thanks
Correction *Rayden not Raiden.Originally Posted by raiden
Anyways,
You have,
$\displaystyle 2x^3-x^2-8x+4$
Group terms as,
$\displaystyle (2x^3-8x)-(x^2-4)$
Factor,
$\displaystyle 2x(x^2-4)-(x^2-4)$
Factor again,
$\displaystyle (x^2-4)(2x-1)$
Factor again,
$\displaystyle (x+2)(x-2)(2x-1)$