can you explain this question for me? I don't quite understand it. Thank you in advance.
$x^2+1$ is a factor of $f(x)$. Which of the following is TRUE?
$\text{a)}\qquad f(-1)=0 \qquad\qquad\qquad\qquad\quad\,\,\, \text{d)}\qquad f(x)\text{ has an $x$-intercept of $1$}$
$\text{b)}\qquad f(x)\text{ has a $y$-intercept of $-1$.} \qquad \text{e)}\qquad f(0)=1$
$\text{c)}\qquad f(i)=0\text{ where $i=\sqrt{-1}$}$
We say that $x^2+1$ is a factor of the polynomial $P(x)$ is there is a polynomial $Q(x)$ such that $(x^2+1)Q(x)=P(x)$.