Polynomials stuff

1. Sep 19, 2010

Kyoma

i'm pretty new to polynomials and I have qns, which I do not know how to solve.

x5 + ax3 + bx2 - 3 = (x2 - 1)Q(x)- x - 2

Q(x) is a polynomial. Solve a and b.

I know the degree of Q(x) is 3, so I subst Q(x) into x3, but I got stuck.

2. Sep 19, 2010

Mentallic

You don't need to know what Q(x) is. The zeroes of $$x^2-1$$ are $$x=\pm 1$$ so if you substitute x=1 into the entire equality, that Q(x) part cancels since anything times zero is zero (your 'anything' is the Q(x)) and then you'll get an equation in a and b. Then substitute the other value of x to get another equation in a and b. Solve simultaneously and you're done!

3. Sep 19, 2010

Kyoma

Thank you very much.