Why does a negative times a negative equal a positive?

I use this example

That’s awesome, man

The pattern way and the a(0)=0 both made sense to me. Now I want to see the integer chips!

Excellent explanation as always.

This was an amazing video, professor ✔️

I like method #3! Makes sense and makes me love math even more! Thanks for explaining these concepts.

Thank you for posting these videos. 😊

How about using a tank to kill a fly : (-1)(-1)=e^(i π). e^(i π) =e^(i π + i π) = e^(2 i π) =cos(2π)+ i sin(2π) =1 + i*0 =1