How do you find the sum of the infinite geometric series 2+2/3+2/9+2/27+...? Precalculus Series Infinite Series 1 Answer Ratnaker Mehta Jul 10, 2016 #3.# Explanation: Let #s# denote the reqd. sum. Then, we know that, #s=a/(1-r)#, where, #a=# the first term of the series, and, #r,#common ratio, with #|r|<1#. Here, #a=2#, and #r=#second term/first term#=(2/3)/2=1/3#, hence #|r|<1.# Therefore, #s=2/(1-1/3)=2/(2/3)=3# Answer link Related questions What are some examples of infinite series? Can an infinite series have a sum? What are some examples of convergent series? What are common mistakes students make with infinite series? How do I use an infinite series to find an approximation for pi? How do I find the sum of the infinite series 1 + #1/5# + #1/25# +... ? How do I find the sum of the infinite series #1/2# + 1 + 2 + 4 +... ? What are some examples of divergent series? How do you find the sum of the infinite geometric series 1/2+1/4+1/8+1/16..? How do you find the sum of the infinite geometric series 3-1+1/3...? See all questions in Infinite Series Impact of this question 4967 views around the world You can reuse this answer Creative Commons License