# Precalculus : Sigma Notation

## Example Questions

### Example Question #21 : Sequences And Series

Write the following series in sigma notation.

Explanation:

To write in sigma notation, let's make sure we have an alternating sign expression given by:

Now that we have the alternating sign, let's establish a function that increases by  per term starting at . This is given by

Putting it all together,

### Example Question #22 : Sequences And Series

Compute:

Explanation:

In order to solve this summation, substitute the bottom value of  to the function, plus every integer until the iteration reaches to 5.

### Example Question #11 : Sigma Notation

Evaluate:

Explanation:

To evaluate this, input the bottom integer into the expression . Repeat for every integer following the bottom integer until we reach to the top integer .  Sum each iteration.

Add these terms for the summation.

### Example Question #12 : Sigma Notation

What is the proper sigma sum notation of the summation of  ?