A real number is any number that can be found on the number line. They can be either rational (such as 2/3, 4.12 or -2.78) or irrational (such as √2 or π). Real numbers can also be positive or negative, whole or fractional.

All real numbers are either included in the rational or irrational set, although some numbers such as 0 and 1, can be classified as belonging to both sets. Real numbers are also used to represent physical quantities, such as time, distance, speed and temperature.

## What is not a real number?

A real number is any number that is part of the real number system, which includes all the positive and negative numbers containing decimal points, fractions, and irrational numbers. Anything that is not a real number does not exist or cannot be quantified and is often referred to as imaginary or complex numbers.

Examples of imaginary numbers include √-1 and the square root of any negative number. Complex numbers are a combination of real and imaginary numbers, often written as a + bi, where a is the real part, b is the imaginary part, and i is the imaginary unit.

## How do you tell if a zero is real or not?

The best way to tell if a zero is real or not is to look at the graph of the given equation. If the graph of the equation crosses the x-axis at a particular point, then it means that a zero exists there.

However, if the graph of the equation only touches the x-axis at a specific point but never crosses it, then it means that the zero is not a real zero. To further confirm whether the zero is real or not, you can try to solve the equation for the zeros by setting the equation equal to zero and check to see if the equation has real solutions.

If the equation has real solutions, then it means that the zero is real, but if the equation has no real solutions, then it means that the zero is not real.

## Does 0 belong to R?

Yes, 0 belongs to the set of real numbers, commonly denoted by ‘R’. All real numbers, including 0, are elements of the set of real numbers. Real numbers can be classified as either rational or irrational.

0 is an example of a rational number because it can be expressed as the quotient of two integers (i.e. 0/1). Additionally, real numbers can be negative, positive, or equal to zero. 0 is a number that is equal to zero and it is also an element of the set of real numbers.

## How do you prove 0 is a real number?

0 is a real number because it is a rational number that can be expressed as the quotient of two integers (0/1). This is different from an irrational number, which cannot be expressed as the quotient of two integers.

The number 0 is also used as an additive identity; it is neither positive nor negative and its presence does not change a number. Furthermore, it is not a complex number, since it does not involve the square root of any negative number.

All of this evidence makes it clear that 0 is a real number.