00:04
Which of the following are roots of the polynomial? well, i'm going to use rational root theorem to find the possible roots.
00:14
Rational root theorem tells me to take the factors of the constant, which in this case, negative 6, over the factors of the leading coefficient, which is 1.
00:30
So i'm going to get 1, 2, 3, and 6.
00:36
I'm going to go to my calculator, i'm going to put in this function, and i'm going to see which of these zeros gives me a zero.
00:45
And i can see that f of 2 equals 0.
00:50
I'm now going to use that zero to bring this cubic down to a quadratic degree.
00:58
Bring down the 1, and i get x squared minus 5x plus 3.
01:09
So a is 1, b is negative 5, and c.
01:13
Is 3.
01:14
I'm going to now use the quadratic formula to find the other roots.
01:19
Opposite of b, so that's 5, plus or minus b squared, minus 4a, c, the whole thing over 2a...