Answer:
Step-by-step explanation:
A geometric series is one where each term is multiplied by a constant value known as r to get the next term
Sum of n terms of a geometric series is
[tex]\frac{a(r^n-1}{r-1},|r|>1\\\frac{1-r^2}{1-r},|r|<1[/tex]
Sum of infinite series is obtained as the limiting value of this sum when n tends to infinity
We find that only when |r|<1, r power n tends to 0 as n tends to infinity.
Other r power n diverges.
Hence geometric series infinite sum formula is valid only when
|r|<1 since the series sum converges to a finite value
