 Proof that π is irrational

Assuming $\pi =a/b$ and integrating a suitably normalized polynomial times $\sin x$ produces a positive integer that tends to zero as the polynomial degree grows. This contradiction proves that $\pi$ is an irrational number.

The proof that π is irrational was first established by Johann Lambert in 1768. His proof is somewhat complex and relies on properties of continued fractions, but I can provide a high-level overview of the concepts involved in proving the irrationality of π. ### Overview of Lambert's Proof 1. **Definitions**: A number is irrational if it cannot be expressed as a fraction of two integers.