Q.21SGR - Algebra 2

Question

Name the sets of numbers to which each number belongs.

 $\sqrt{18}$

Step-by-Step Solution

Answer

$\sqrt{18}$ belongs to the sets of irrational number and real number.

Step 1. Define different sets

• The set $\left\{1,2,3,4,5,...\right\}$ is called the set of natural number. 
• The set $\left\{0,1,2,3,4,5,...\right\}$ is called the set of whole number. 
• The set $\left\{-3,-2,-1,0,1,2,3,...\right\}$ is called the set of integer number. 
• The set of rational number has numbers in the ratio form $\frac{m}{n}$, where $m$ and $n$ are integers and $n$ is non-zero. The decimal form of a rational number is either a terminating or repeating decimal.
• A real number that is not rational is irrational. The decimal form of an irrational number is neither terminating nor rational.
• Combine sets of rational and irrational number is real number.

Step 2. Relationship between different sets

Following vein diagram shows relationship between different sets

Where, the symbols denote 

N- Natural number

W- Whole number

Z- Integers

Q- Rational number

I- Irrational number

R- Real numbers

Step 3. Find the sets to which 18 belongs

$\sqrt{18}$ is an irrational number and a real number.

Thus, $\sqrt{18}$ belongs to the sets of irrational number and real number.