### Home > APCALC > Chapter 9 > Lesson 9.1.1 > Problem 9-15

9-15.

Ying has a different method for summing an infinite series. Here are her steps:

1) Let

the sum.2) Separate the first term from the rest of the series.

3) Factor the rest of the terms

*so that the remaining factor is*. 4) Substitute

for the other factor.5) Solve for

.

Apply Ying’s method to the following problem. The first three steps are done for you. Copy them, then complete the solution.

Problem:

Start of Solution: