yes, that is fine.

no. if you plug in x = 3 or x = -3, you do not get zero, do you?Would it be -3 and 3?

Hint: treat this as the difference of two squares. (write as )

any polynomial in x can be written in the form:How do I write f(x) into factored form?

where a,b,c,... are the roots of the polynomial.

you found the zeros (i did not check if they were correct by the way, so check yourself), so mark these on the x-axis. between the zeros, check if the function is positive or negative. so for example, if one zero was 1 and another was 3, you would plug in something like 2 into the polynomial. if the value is positive, you know the graph is above the x-axis, if negative, it is below. do this for all the intervals. we have an odd degree polynomial, so one end will go to infinity while the other goes to negative infinity. when you have all the zeros marked and the positions of the graph in each intervals, just draw the curve through them....And how would I draw an approximate sketch of that?

hope that helped. i had to be somewhat vague on purpose since this is a test...