00:01
We want to solve the equation 4x squared minus 4x minus 1 equals 0 by completing the square.
00:06
To do this, since the leading coefficient is not 1, let's make it 1 by dividing everything by 4.
00:14
So it becomes x squared minus x minus 1 4th equals 0.
00:20
Now i'm going to add 1 4th to both sides so that we're leaving some room to complete the square.
00:28
By completing the square, we'll be able to write the left hand.
00:31
Hand side is a perfect square, which then we will apply the square root property.
00:37
To do this, we take the coefficient on the x term, which is negative one, take half of it, negative one, which is what's going to be in our perfect square, and then square it, which would be positive one -fourth.
00:55
So we're adding one -fourth to both sides.
01:00
Well, one -fourth plus one -fourth is two -fourths, or one half.
01:05
And now we can apply the square root property...