(*0j1×⍵) = (cos ⍵)+0j1×(sin ⍵)

   ○1
3.14159

   cos ○1
¯1
   sin ○1
1.22461e¯16

   (cos ○1)+0j1×(sin ○1)
¯1j1.22465e¯16

   1 + * ○ 0j1
0

I used to think math was no fun,
’Cause I couldn’t see how it was done.
    Now Euler’s my hero,
    For I now see why 0
Equals e to the π i plus 1.

e raised to the π times i,
And plus 1 leaves you nought but a sigh,
    This fact amazed Euler,
    That genius toiler,
And still gives us pause, bye the bye.

              — Anon y Mous