Hello,

Factor

you can see that 1 is a root of this polynomial. Thus (x-1) is a factor of the polynomial.

solve for a,b in

you'll get two roots, p and q :

(p=-1 and q=2)

then make a table, like they said :

between - infinity and -1, (x-1)<0, (x+1)<0, (x-2)<0, so the polynomial is...

between -1 and 1, ...

between 1 and 2, ...

between 2 and infinity, ...

if you have no idea on how to do this, just say it here, but please try to think about it