Which of the following is an irrational number?

a. [tex]\sqrt{12}[/tex]
b. [tex]\sqrt{9}[/tex]
c. [tex]\frac{7}{3}[/tex]
d. [tex]\frac{0}{11}[/tex]



Answer :

To determine which of the given numbers is irrational, we need to analyze each option step-by-step.

1. Option a: [tex]\(\sqrt{12}\)[/tex]

The square root of 12 is [tex]\(\sqrt{12}\)[/tex]. We need to check if this number can be expressed as a ratio of two integers.

[tex]\(\sqrt{12}\)[/tex] simplifies as follows:

[tex]\[ \sqrt{12} = \sqrt{4 \times 3} = \sqrt{4} \times \sqrt{3} = 2\sqrt{3} \][/tex]

[tex]\(\sqrt{3}\)[/tex] is known to be an irrational number (it cannot be expressed as a ratio of two integers). Therefore, [tex]\(2\sqrt{3}\)[/tex] is also irrational.

2. Option b: [tex]\(\sqrt{9}\)[/tex]

The square root of 9 is [tex]\(\sqrt{9}\)[/tex]. We can simplify this directly.

[tex]\[ \sqrt{9} = 3 \][/tex]

Since 3 is an integer, it is a rational number.

3. Option c: [tex]\(\frac{7}{3}\)[/tex]

The number [tex]\(\frac{7}{3}\)[/tex] is a fraction where both the numerator (7) and the denominator (3) are integers.

A number in the form of a fraction [tex]\(\frac{p}{q}\)[/tex] where [tex]\(p\)[/tex] and [tex]\(q\)[/tex] are integers with [tex]\(q \neq 0\)[/tex] is by definition a rational number. Thus, [tex]\(\frac{7}{3}\)[/tex] is a rational number.

4. Option d: [tex]\(\frac{0}{11}\)[/tex]

The number [tex]\(\frac{0}{11}\)[/tex] is a fraction where the numerator is 0 and the denominator is 11 (an integer).

Any number with 0 in the numerator is equal to 0, provided the denominator is a non-zero integer.

[tex]\[ \frac{0}{11} = 0 \][/tex]

Since 0 is an integer, it is a rational number.

After analyzing all the options:

- Option a ([tex]\(\sqrt{12}\)[/tex]) is irrational.
- Option b ([tex]\(\sqrt{9}\)[/tex]) is rational.
- Option c ([tex]\(\frac{7}{3}\)[/tex]) is rational.
- Option d ([tex]\(\frac{0}{11}\)[/tex]) is rational.

Hence, the irrational number among the given choices is:
[tex]\[ \boxed{1} \][/tex]