But before we move forward, let's get a notation for how we can represent these sums without necessarily having to write out all of the digits or having to keep doing this dot, dot, dot, plus notation.

And that notation is Sigma notation.

That's to infinity dot dot dot.

Cisco Dot Dot

So this is just dot dot dot.

It's just all notation there's nothing particular about notation.

Dot.

Sigma notation up.

This is another notation.

I always forget notation.

Yeah, see that notation?

Atra Dot

Dot size

The dot!

Dot, this is a vector, so dot this guy right here, dot dr.

4 times x dot y times x dot y.

This dot product right here is that dot product.

0, 1 dot my unit vector dot u1, u2.

And I'll introduce my notation.

This is just my notation.

I'm just making up notation.

These are all equivalent notation.

I'll use the same notation.

This is just different notation.

We've seen this notation before.

And the notation is PV

Very, very specific encrypted notation.

A dot B.

GPS tracking dot.

Times this guy over here. v2 dot v2 minus v2 dot v1 squared over v1 dot v1.

Well not just dot products but dot products scaling different vectors.

A dot B, we are going to subtract A dot B

And you signify the dot product by saying a dot v.

What's x dot x? x dot x is just the magnitude.

I have an x dot y and a y dot x.