Summation Notation
Summation Notation
Example 2
Find the value of the following summation:![SumEx2-1 SumEx2-1](https://claregladwinresd.glk12.org/pluginfile.php/1013/mod_book/chapter/615/Sequence_and_Series/Images/SumEx2-1.png)
Step 1. Determine if the sequence is arithmetic or geometric.
The function representing the sequence is exponential. Therefore the summation represents a geometric series.
Step 2. Determine a1, r and n.
![SumEx2-2 SumEx2-2](https://claregladwinresd.glk12.org/pluginfile.php/1013/mod_book/chapter/615/Sequence_and_Series/Images/SumEx2-2.png)
![SumEx2-3 SumEx2-3](https://claregladwinresd.glk12.org/pluginfile.php/1013/mod_book/chapter/615/Sequence_and_Series/Images/SumEx2-3.png)
![SumEx2-4 SumEx2-4](https://claregladwinresd.glk12.org/pluginfile.php/1013/mod_book/chapter/615/Sequence_and_Series/Images/SumEx2-4.png)
Step 3. To find the series, substitute and solve.
![SumEx2-5 SumEx2-5](https://claregladwinresd.glk12.org/pluginfile.php/1013/mod_book/chapter/615/Sequence_and_Series/Images/SumEx2-5.png)
![SumEx2-6 SumEx2-6](https://claregladwinresd.glk12.org/pluginfile.php/1013/mod_book/chapter/615/Sequence_and_Series/Images/SumEx2-6.png)
![SumEx2-7 SumEx2-7](https://claregladwinresd.glk12.org/pluginfile.php/1013/mod_book/chapter/615/Sequence_and_Series/Images/SumEx2-7.png)
![SumEx2-8 SumEx2-8](https://claregladwinresd.glk12.org/pluginfile.php/1013/mod_book/chapter/615/Sequence_and_Series/Images/SumEx2-8.png)
![SumEx2-9 SumEx2-9](https://claregladwinresd.glk12.org/pluginfile.php/1013/mod_book/chapter/615/Sequence_and_Series/Images/SumEx2-9.png)