Question

How do you find the sum of the infinite geometric series t1=5 and r = -2?

Answer 1

It diverges till negative infinity and has no sum.

Explanation:

There is a theorem that states that an infinite geometric series of form `sum_(n=1)^ooar^(n-1)` converges to `a/(1-r)` iff and only if `|r|<1`.

So in this case, `|r|=|-2|=2>1` hence by this theorem the series does not converge.