00:01
So we have a x squared plus c y squared plus f is equal to zero.
00:08
And we know that a does not equal zero, c does not equal zero, and also f does not equal zero.
00:17
And we know that a and b are opposite signs.
00:22
Now we don't know which one's positive, which one's negative.
00:26
And we want to show that this is going to end up being a hyperbola.
00:30
That's centered at 0 .0.
00:31
So we would take this and we would subtract.
00:39
Let me get rid of that.
00:41
Negative there.
00:43
And we would subtract f from both sides.
00:46
Now, we don't know whether f is positive or negative.
00:49
But we would, regardless, we would divide both sides by negative f.
00:56
And this would end up giving us a 1 here.
00:58
And then we would have this a and i can even write it like so, whoops, trying to get the eraser feature on here.
01:11
And we would end up writing it as x squared over, and we could have negative f over a.
01:18
Get rid of that mark there.
01:20
And then we would have minus, and then i would have this y squared, over f over c equals one and now we know that a and i'm sorry this is supposed to be c are opposite signs so we know if a is positive then we would know b or excuse me i keep saying b i don't know why i didn't use b i would have liked to have been b we know that c would have to be negative if this is the case then we would have if a is positive and let's just make our, when we go write down two cases for f, let's just assume that f is something that is positive...