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## Is the set of rational numbers denumerable?

The set of positive rational numbers (positive fractions) is denumerable.

**How set of rational numbers is countable?**

The set of all rationals in [0, 1] is countable. Clearly, we can define a bijection from Q ∩ [0, 1] → N where each rational number is mapped to its index in the above set. Thus the set of all rational numbers in [0, 1] is countably infinite and thus countable.

**How do you prove something is rational?**

To decide if an integer is a rational number, we try to write it as a ratio of two integers. An easy way to do this is to write it as a fraction with denominator one. Since any integer can be written as the ratio of two integers, all integers are rational numbers.

### Is rational numbers countable or uncountable?

The set of rational numbers is countable. The most common proof is based on Cantor’s enumeration of a countable collection of countable sets.

**How do you prove that a number is rational or irrational?**

Numbers that can be represented as the ratio of two integers are known as rational numbers, whereas numbers that cannot be represented in the form of a ratio or otherwise, those numbers that could be written as a decimal with non-terminating and non-repeating digits after the decimal point are known as irrational …

**What is Denumerable in math?**

(mathematics) Capable of being assigned numbers from the natural numbers. Especially applied to sets where finite sets and sets that have a one-to-one mapping to the natural numbers are called denumerable.

## How do you prove that the rational numbers form a set?

To prove that the rational numbers form a countable set, define a function that takes each rational number (which we assume to be written in its lowest terms, with ) to the positive integer . The number of preimages of is certainly no more than , so we are done.

**How do you find the product of two rational numbers?**

The product of two rational numbers is equal to half of their sum if one of the rational number is 3/2 find the other

**Is the sum of two rational numbers always a rational number?**

So you have an integer in the denominator. So now the product is a ratio of two integers right over here, so the product is also rational. So this thing is also rational. So if you give me the product of any two rational numbers, you’re going to end up with a rational number. Let’s see if the same thing is true for the sum of two rational numbers.

### Is 0 a rational number?

It is a rational number. 0 is an integer. All integers are rational numbers. Integers can be written as a fraction using 2 integers (that’s the definition of a rational number): 0 = 0/1