$\"\"$

The series is $\"\"$ .

$\"\"$ , the series is geometric series.

The geometric series is $\"\"$ is convegent if $\"\"$ and its sum is $\"\"$ .If $\"\"$ , the geometric series is divergent. \ \

Find the common ratio.

When $\"\"$ then $\"\"$ .

Therefore, the common ratio is $\"\"$ .

$\"\"$ .

Since $\"\"$ the series is convergent.

Find the sum of the series.

Substitute $\"\"$ and $\"\"$ in $\"\"$ .

$\"\"$ .

The sum of the series is $\"\"$ .

$\"\"$

The series is convergent.

The sum of the series is $\"\"$ .