00:02
Let's find the inverse of the function.
00:04
So we start by switching x and y.
00:07
So that would give us x equals y squared minus y.
00:11
Now we want to isolate y.
00:13
So this is a little tricky because it's very difficult to isolate y in a quadratic function unless you change it to a different form.
00:21
So what i'm going to do is complete the square.
00:25
And to do that, i'm going to figure out what i need to add to make a perfect trinomial square.
00:30
So we have y squared minus 1y plus.
00:33
Now to get the number that we add, we take half of the coefficient on y, so that would be negative one half, and we square it, and that would be one -fourth.
00:43
So we need to add one -fourth.
00:44
Now we can't just add one -fourth to one -forth to one -side of the equation...