# Maximum value

## Homework Statement

I'm asked to find the maximum value of $h$ such that $\mu = \lambda h\;\;(\lambda \in \mathbb{R})$ satisfies: $$|1+\mu + \frac{1}{2} \mu ^2 + \frac{1}{6} \mu ^3| < 1$$

## The Attempt at a Solution

My hurdle is solving $1+\mu + \frac{1}{2} \mu ^2 + \frac{1}{6} \mu ^3=1$ to find the interval $\mu\in (?,?)$ which satisfies $$|1+\mu + \frac{1}{2} \mu ^2 + \frac{1}{6} \mu ^3| < 1$$