### Comment:
not developed or discovered by euler 
  
 Actual euler identity: 
  
 1/(1 * 1) + 1/(2 * 2) + 1/(3 * 3) + ... = pi * pi / 6

### REPLY:
That's just the solution to the [Basel problem](https://en.wikipedia.org/wiki/Basel_problem). 
  
 Euler did publish [Euler's formula](https://en.wikipedia.org/wiki/Euler%27s_formula), the general equation that simplifies to Euler's identity when *x* = pi. While Euler didn't discuss it, it's not exactly a monumental step to try plugging in pi. I'm sure he realized the simplification.

### END.