00:01
So we have here, we have a graph of a hyperbola, and we want to find the equation for this hyperbola from the graph.
00:09
So the first thing that we know is that our vertices of the graph are at the points 0 plus or minus the square root of 2.
00:16
We also know that this graph passes through this point here, which is the point 2 -2, and we also know that the focal axis of the graph is the y -axis.
00:26
So we're going to be looking for some equation that looks like this.
00:29
We're going to be looking for an equation that is y squared over a squared minus x squared over b squared is equal to 1.
00:36
So we just have to find what a and b are equal to.
00:40
So first we can use the vertices of the graph to find our a because our vertices are just found at the points 0 plus or minus a, which means that a is just equal to the square root of 2.
00:53
So a is equal to the square root of 2.
00:56
And now that we have a value for a and we know a point on the graph, we can see that.
01:00
Solve for the value of b by plugging in negative 2 for y and 2 for x into this equation over here and root 2 for a.
01:10
So we'll write all of this out again.
01:12
So we'll have, so in the place of y, we'll put negative 2.
01:17
We'll have negative 2 squared, negative 2 squared, and we'll put this over a squared and root 2 squared is just 2.
01:28
So we have negative 2 squared over 2, minus, and we'll put this over a squared, and root 2 squared, and our x is 2, so we have 2 squared, 2 squared over b squared is equal to 1...