Question

I need to write the series and say which is it's tendency

Answer 1

\[\sum_{n=1}^{infinite}\frac{ 1 }{ 2^{n} }\]

Answer 2

So... 1/2 + 1/4 + 1/8 + 1/16+...

Answer 3

Is this correct?
r=0.5
a= 1

\[Sn=\frac{ a }{ 1-r }\]

so Sn=1/0.5=2