00:01
Okay, to find the zeros of this, first i have to list what the possible zeros are.
00:11
And to do that, i take all the factors of the constant, and the constant of this function is 99, and divide by all the factors of the leading coefficient.
00:28
And the leading coefficient of this problem is 1.
00:37
So the factors of 99 would be plus or minus 1 and 99, 3 and 33, 9 and 11.
00:54
And they'd all be plus or minus.
00:57
And since i'm dividing them all by 1, that's the only factor of 1.
01:03
I really don't have to worry about the bottom.
01:07
Okay, so what we're going to do is synthetic division with those zeros until we find one that gives us a remainder of zero.
01:16
So let's set this problem up for synthetic division.
01:20
We have 1x to the fourth, 10x to the third, negative 20x to the second, 90x to the first, and a 99.
01:36
And the first number that i'm going to try is positive 1.
01:44
Okay, so in synthetic division, the first thing you do is multiply the number under the line by the number in the box.
01:55
So 1 times 1 is 1.
01:59
Then you add those numbers.
02:02
10 plus 1 is 11.
02:05
Then you multiply again the number under the line times the number in the box.
02:11
11 times 1 is 11.
02:14
And you just keep repeating this process.
02:16
Negative 20 plus 11 is negative 9.
02:20
Negative 9 times 1 is negative 9.
02:25
Negative 90 plus negative 9 is negative 99.
02:31
Negative 99 times 1 is negative 99.
02:36
And that gives me a remainder of zero...