So now, I started from the big problem, and I couldn't answer it.

And let's take a super simple example, a ridiculously simple example.

And that's what we set out to figure out in the beginning.

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.

Adjust the microscope's focus.

Set the focus of the microscope.

Adjust the focus of the microscope.

We have focused on the worst case scenario.

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.

Ellipse by Focuses Point

This is less than.

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,

Hyperbola by Focuses Point

Now we're asking you what is the focal length if an object of size 20 m that is 400 meters out if we observe it to be 1 mm on our projection surface.

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

And this is greater than, so 2 and 1 2 is greater than 11 10.

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.

And what's the brilliant idea he had?

It's an infinitesimally small amount of time in space.

That's just this distance right here.

35mm equivalent focal length

That's this distance right there.

And you enter that space, and you feel like, Wow!

Requires great focus.

We focus on Parker. And move it.

In this case the major axis is the vertical axis, so the focuses are going to sit here and here, and in this case, the focal lengths are going to be vertical down from the origin and vertical up from the origin, and we get, instead of it being a squared minus b squared, now since b is larger than a, the focal length, which is this, is going to be equal to b squared minus a squared.