Determine whether the number $\frac{\pi}{5}$ is rational or irrational.

Number TheoryRational NumbersIrrational NumbersReal NumbersPi
2025/3/21

1. Problem Description

Determine whether the number π5\frac{\pi}{5} is rational or irrational.

2. Solution Steps

A rational number can be expressed as a fraction pq\frac{p}{q}, where pp and qq are integers and q0q \ne 0. An irrational number cannot be expressed in this form.
We know that π\pi is an irrational number. Multiplying or dividing an irrational number by a non-zero rational number results in an irrational number. Since 15\frac{1}{5} is rational and π\pi is irrational, π5=15π\frac{\pi}{5} = \frac{1}{5}\cdot\pi is irrational.

3. Final Answer

Irrational

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