?How do you find the sum of the infinite geometric series # 6^n/7^n#? Precalculus Series Infinite Series 1 Answer Cesareo R. Nov 16, 2016 #7# Explanation: #(x^(n+1)-1)/(x-1)=1+x+x^2+cdots+x^n# then #sum_(k=0)^n (6/7)^k = ((6/7)^(n+1)-1)/((6/7)-1)# Now, #lim_(n->oo)sum_(k=0)^n (6/7)^k=lim_(n->oo) ((6/7)^(n+1)-1)/((6/7)-1)=1/(1-6/7)# because #lim_(n->oo)(6/7)^n=0# so finally #sum_(k=0)^oo (6/7)^k = 7# 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 4188 views around the world You can reuse this answer Creative Commons License