This is amazing

This is crazy, how was this found 🤯

i understood everything

this is amazing an d i love you

fire

👍👍👍

this was amazing. I tried to derive the arctan (sec x  - tan x ) identity a couple different ways with deMoivre and also setting (sec x  - tan x ) to tan(a+b theta) but I couldnt get these to work out. i would love a method that doesnt require writing 1 as tan(pi/4), anyone have any ideas?

why can you swap the sum and the integral when it is a power series? 2:16