00:01
I don't know if you're allowed to use a graph and calculator to help you out.
00:06
But if you use a graph and calculator, if you're allowed to, and you looked at the x intercepts.
00:18
I'm trying to be careful about this.
00:20
So it's at negative 3, negative 1 .5, and 1, 2, 3, 4, 5.
00:28
So the graph of this looks something like this, and that will help you because where you cross the x -axis will be your x intercepts.
00:41
Now the other way to test rational zeros is to find all of these factors, factors of the leading coefficient, and then all the factors of the constant at the end.
00:51
And so i make my students list out possible rational roots, and those are all of the, factors of the constant so positive or negative one three and all of these are positive negative just trying to save some time as well as all of the factors of these numbers so one half three halves five halves and fifteen halves and at this point you can just go through synthetic division now i know my synthetic division looks a little bit different than other peoples i like to write it like this and you know something is a root if you get a remainder of zero.
01:35
So how do you do synthetic division then? you bring numbers down and you multiply by what you think is the actual factor.
01:42
So 2 times negative 3 is negative 6.
01:45
And you add straight down.
01:48
Negative 9, and you multiply.
01:50
So it's positive.
01:53
I knew i messed up...