# Math Riddle

**URL:** <https://forum.kirupa.com/t/math-riddle/213295>\
**Category:** random\
**Created:** [January 18, 2007, 2:59pm UTC](https://forum.kirupa.com/t/math-riddle/213295 "2007-01-18T14:59:21Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Yeldarb](https://avatars.discourse-cdn.com/v4/letter/y/51bf81/32.png) [@Yeldarb](https://forum.kirupa.com/u/Yeldarb)\
**Post date:** [January 18, 2007, 2:59pm UTC](https://forum.kirupa.com/t/math-riddle/213295/1 "2007-01-18T14:59:21Z")

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Well it’s not really a riddle I suppose. But I was bored in Calc II recitation today so I was daydreaming and came up with this.

What is unique and common about these two functions? (Not found in any other function)

f(x) = e^x  
and  
f(x) = 0