00:01
So let's start with the foci.
00:04
If the foci are at 0, 2, and 0 negative 2, then we know the center must be 0, 0 because that's the exact middle between those 2.
00:14
This also tells us that the vertical axis is the major axis because the foci are always on the major axis.
00:22
And it tells us that our c equals 2 because the foci which have a major axis that is the vertical one will be at 0 plus or minus c.
00:32
Now that we have c equals 2, we can also find our a, because e is equal to c over a.
00:40
So if e equals 1 9th, 1 9th equals 2 divided by a, then we just solve it.
00:49
I'm going to cross multiply, and we get a is equal to 18, because a times 1, a 9 times 2 is 18.
01:01
Then to find the b, we're going to do the formula of c squared equals a squared minus b squared.
01:08
So our c is 2, which means that 4 will equal a squared, which is 18 times 18, gives us 324 minus b squared.
01:19
So we're going to subtract that 324...