00:01
We have a function and we are wanting to change this quadratic function into its vertex form.
00:07
The vertex form of a parabola is f of x equals a times x minus h squared plus k.
00:20
To change it into that form, we should notice that we do have this 4 in front of the x squared.
00:25
So we're going to pull that out front of the parentheses.
00:29
Now, if we divide 4 out, we would have x squared and then minus 20x divided by 4 would be minus 5x.
00:43
However, we want it in the form of quantity x minus h squared.
00:48
So we have to do a process called completing the square.
00:53
To complete the square, we have to figure out what the third term should be.
01:00
The third term can come from the second term.
01:03
What we do is we divide that number by 2 and then square it...