Waste less time on Facebook — follow Brilliant.

Sum of Arithmetic Sequence

The sum of \(n\) terms in an arithmetic progression can be obtained by taking the number of terms being added \(n\), multiplying by the sum of the first and last number in the sum, and then dividing by 2:

\[ \frac{n(a_1 + a_n)}{2}.\]

For example:

\[1+4 +7+10+13 = \frac{5(1 + 13)}{2} = \frac{5 \times 14}{2} = 35.\]

Note by Arron Kau
2 years, 2 months ago

No vote yet
1 vote


There are no comments in this discussion.


Problem Loading...

Note Loading...

Set Loading...