Derive and use the finite geometric series formula to solve problems such as mortgage-payment models.
Find the sum of a finite geometric series from the first term, ratio, and term count
Problem
Find the sum of the finite geometric series with first term \(3\), common ratio \(2\), and \(6~\text{terms}\).
Big Picture
What this problem is really about
Organize the series data before touching the finite-sum formula: first term, common ratio, and actual number of terms. The exponent in the formula is that term count, even when a zero-based list would end one index earlier. Keeping the first-term multiplier outside the fraction also prevents a correct geometric factor from being mistaken for the whole sum.
Inside Gozunta
Turn the preview into practice.
More than a preview
Gozunta lets you study this problem—and more than 10,000 others.
Create targeted learning sessions, use hints, check your answer, read the walkthrough, watch the video, print the work, and track your progress.
