Question

Find the sum of the infinite series 1/3+1/9+1/27+... if it exists

Answer 1

\[s=\frac{ 1 }{ 3 }+\frac{ 1 }{ 9}+\frac{ 1 }{27 }+...\]\[a _{1}=\frac{ 1 }{ 3 }\]\[q=\frac{ 1 }{ 3 }\]
then use this formula
\[s=\frac{ a_{1} }{ 1-q }\]

Answer 2

thank you