Partial sums of arithmetic series
key notes:
A sequence is an ordered list of numbers. This list can have a finite number of terms or infinitely many terms.
- A series is the sum of a sequence of numbers.
- The nth partial sum (Sn) of a series is the sum of its first n terms.
A sequence is an ordered list of numbers. This list can have a finite number of terms or infinitely many terms.
A series is the sum of a sequence of numbers.
The nth partial sum (Sn) of a series is the sum of its first n terms.
Learn with an example
🔔 Find the third partial sum of the series.
5 + 8 + 11 + 14 + 17 + 20 + ⋯
Write your answer as an integer or a fraction in simplest form.
S3=____
Look at the series.
5 + 8 + 11 + 14 + 17 + 20 + ⋯
The third partial sum, S3, is the sum of the first three terms.
S3 = 5 + 8 + 11 = 24
🔔 Find the third partial sum of the series.
8 + 11 + 14 + 17 + 20 + 23 + ⋯
Write your answer as an integer or a fraction in simplest form.
S3=
Look at the series.
8 + 11 + 14 + 17 + 20 + 23 + ⋯
The third partial sum, S3, is the sum of the first three terms.
S3= 8 + 11 + 14 = 33
🔔 Find the third partial sum of the series.
4 + 11 + 18 + 25 + 32 + 39 + ⋯
Write your answer as an integer or a fraction in simplest form.
S3=
Look at the series.
4 + 11 + 18 + 25 + 32 + 39 + ⋯
The third partial sum, S3, is the sum of the first three terms.
S3= 4 + 11 + 18 = 33
let’s practice!🖊️
