By using method of differences, how can we get f(n)-f(0) but y not f(1)-f(n-1), from ∑f(r)-f(r-1)? Precalculus Series Summation Notation 1 Answer Steve M Jul 18, 2017 See: https://socratic.org/questions/summation-of-series-method-of-differences-when-we-use-f-r-f-r-1-how-can-we-know-#453142 Answer link Related questions What is summation notation? What are some examples of summation notation? What is a sample summation notation problem? How do I use summation notation on a calculator? How do I use summation notation with infinity? How do I use summation notation to write the series 2 + 4 + 6 +... for 10 terms? How do I use summation notation to write the series 2.2 + 8.8? How do I use summation notation to write the series 2.2 + 6.6? How do I use summation notation to write the series 2.2 + 6.6 + 11? What is the difference between a sequence and a series in math? See all questions in Summation Notation Impact of this question 1620 views around the world You can reuse this answer Creative Commons License