Is Pi rational or irrational?
Pi is an irrational number, which means it cannot be expressed as a simple fraction or ratio of two integers. Instead, it is an infinite, non-repeating decimal.
Proof that Pi is irrational
One of the most famous proofs of Pi's irrationality was done by Johann Lambert in 1761. He showed that if Pi were rational, then it could be expressed as a repeating decimal. However, he also showed that Pi cannot be expressed as a repeating decimal, and therefore it must be irrational.
Decimal expansion of Pi
The decimal expansion of Pi is infinite and non-repeating, which means that there is no pattern to the digits. The first few digits are 3.14159, but the decimals go on forever without repeating.
Uses of Pi
Although Pi is an irrational number, it is still an important mathematical constant. It is used in a variety of calculations and formulas, including:
- Calculating the circumference and area of a circle
- Calculating the volume and surface area of a sphere
- Analyzing waves and vibrations
- Calculating probabilities in statistics
Conclusion
In summary, Pi is an irrational number that cannot be expressed as a simple fraction or ratio of two integers. It is an infinite, non-repeating decimal that is used in a variety of mathematical calculations and formulas.