You can use the digits 1,2,and 3 once only and any mathematical symbols you are aware of, but no symbol is to be used more than once. The challenge is to see if you can make the smallest positive number.
Special rules: You cannot use Euler's number or pi or infinity.
Special thanks to: Rhonda Wendel for Make the most of these digits and for the problem text which was slightly altered.
(In reply to A small idea, an even smaller number
by Brian Smith)
I made a mistake. My equations should read:
cot arctan x=1/x
cot arctan [(.1^-2e3)!]