00:01
So in this example, we have the equation 2 y squared this time.
00:09
We have a 4 y and a 5.
00:11
Now we want to convert this to our other form of our quadratic.
00:15
But to do that, we need to complete the score.
00:17
And if we want to complete the square, we really can't be working with this 2 very well.
00:22
So we're actually going to divide both sides by 2 and rewrite this as x over 2 equals.
00:29
Now we only have 1 y squared, which is what we want, minus 2y plus.
00:34
5 over 2 or 2 and 1 half.
00:36
Now, these two terms are the ones we grouped together.
00:39
So we're going to figure out what we need to add in here to make this a perfect square.
00:43
The magic number to figure that out, we can take our b value, which is our negative 2.
00:48
We can divide it in half and then square it.
00:50
So negative 2 divided by 2 is negative 1, and we can square the negative 1 to get 1.
00:56
So that magic number is plus 1.
00:59
If i add 1, i now have a perfect square trinomial level factor.
01:02
But if i add one, i also need to subtract one on the same side...