How do I write the range of these sequences in set builder notation
/e n is a natural number

( (cos n pi) / 4 )

And

( ((1 + (-1)^n )^n)/(3^n) )

This post was edited by brigadier on Oct 8 2014 09:53pm

{ - 1/4 ; + 1/4 }

{ 0 } u { (4/9)^k | k natural number }