81 as well as all whole numbers are rational numbers. Any number that can be written as a fraction is a rational number. An irrational number can be written as a decimal, but not as a fraction.
An irrational number has endless non-repeating digits to the right of the decimal point. An example of an irrational number would be pi:
π = 3.141592…Chat with our AI personalities
No. The square root of 81 is 9, which is a rational number.
10.01 is a rational number
Rational
Such a product is always irrational - unless the rational number happens to be zero.
The sum of a rational and irrational number must be an irrational number.