We have focused on the worst case scenario.

Ellipse by Focuses Point

An ellipse constructed by its focuses and a point that pertains to it

And hard to keep focus.

A hyperbola constructed by its focuses and a point that pertains to it

Hyperbola by Focuses Point

Focal length

Focal

Focal Length

Focal blur

Focal point

First Focus

Second Focus

Focal Length

Focal length

And this is f2.

And it's for focus.

Well, the first thing you do is though I've never well, we could just figure out the focal length just by plugging into the formula.

That's this distance right there.

Conic by Directrix, Focus Point

Construct a conic with this point as focus

So you know that a is equal to x1.

Focal length of the lens

Well, we just used the distance formula.

Or they can be, I don't want to say always.

Just focus.

Bifocals.

Your focus,

Let's focus on the conversations between our friends and our family and our coworkers and our loved ones.

Her face is in focus.

Show camera aperture and focal length

And let's say I have some other point.

I don't want to focus too much on the tax savings on interest.

And we will see so in a few special cases for this.

A parabola defined by its directrix and focus

And what we want to do is, we want to find out the coordinates of the focal points.

Focal Length

Telescope focal length

Eyepiece focal length

So let's call that a directrix.

That's our directrix and it has the equation y is equal to k.

So what's the reality?

It elevates the temperature.

Parabola by Directrix Focus

Same thing, that's this line.