### Home > CALC > Chapter 9 > Lesson 9.2.2 > Problem 9-72

9-72.

A variant of Ying's trick (manipulating an infinite expression so that the expression appears as a part of itself) can be used in other situations. For example, it can be used to evaluate an infinite "continued fraction" such as: Homework Help ✎

Explain why *S*.

Use the Quadratic Formula to solve for *S*.