Let's say for example, we are asked to evaluate . All this is simply telling us is that we need to find . When you evaluate a factorial, you take the particular number and multiply to each number that preceeded it..
Also, we can break up factorials as well
What if we had to evaluate ?? We need to find something that will cancel out with the
Take note that and Thus, we see that
Does this seem to make sense? Why don't you try the problem applying what I said here.
2) Would you post the exact question? I can't really help out for some information is probably missing.
3) Try to determine a possible zero of the function. Apply long division, and then apply the quadratic forumula to the remainder. You will probably see that you'll get you're complex [imaginary] roots. Keep in mind that real values are complex numbers as well [i.e. ]
I hope this makes sense!