When the polynomial $P(x)$ is divided by $x^2 -1$, the remainder is $3x-1$. What is the remainder when $P(x)$ is divided by $x-1$?
I'm not sure what to do. I know that $P(1)=P(-1)=3x-1$, but I don't think that's how you're supposed to do it.
Any help would be appreciated, thanks.