How do we know that the value of Pi goes on forever?

The pi is the limit.

26th August 2010
How do we know that the value of Pi goes on forever? (Getty)

Asked by: Tasha Ford, Warwick

The Swiss mathematician Johann Lambert proved this around 250 years ago by showing that Pi can’t be expressed exactly as the ratio of one number to another – in other words, it’s an ‘irrational’ number that goes on forever, never repeating itself. While we often use rational values for Pi like 22/7, these are only approximations to its true value, and always repeat after a certain number of decimal places.
 


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