What doesnt describe a rational number?

Answer 1

A rational number is one which can be expressed as a ratio (or a fraction) of two numbers, i.e. a/b. Numbers which cannot be expressed like this, such as the constants e and π (pi), are irrational.

Other numbers which are irrational include:

• the square root of 2, or any other number that isn't a perfect square
• the golden ratio φ, the ratio of two numbers (we'll call them A and B, A being larger than B) such that the ratio of A + B to A is the same as the ratio of A to B
• eπ