Which number produces an irrational number when multiplied by [tex]\frac{1}{4}[/tex]?

A. [tex]\frac{4}{3}[/tex]
B. [tex]\sqrt{12}[/tex]
C. [tex]-\sqrt{36}[/tex]
D. [tex]0.444444 \ldots[/tex]



Answer :

To determine which number produces an irrational number when multiplied by [tex]\(\frac{1}{4}\)[/tex], we need to analyze each given number and perform the multiplication, then check whether the result is irrational.

First, let's define what it means for a number to be irrational:
- A number is irrational if it cannot be expressed as a ratio of two integers, i.e., it has a non-repeating, non-terminating decimal expansion.

Given numbers:
A. [tex]\(\frac{4}{3}\)[/tex]
B. [tex]\(\sqrt{12}\)[/tex]
C. [tex]\(-\sqrt{36}\)[/tex]
D. [tex]\(0.444444 \ldots\)[/tex]

### Multiplications and Checks:

#### A. [tex]\(\frac{4}{3}\)[/tex]
[tex]\[ \frac{4}{3} \times \frac{1}{4} = \frac{4}{3} \cdot \frac{1}{4} = \frac{4 \cdot 1}{3 \cdot 4} = \frac{1}{3} \][/tex]
[tex]\(\frac{1}{3}\)[/tex] is a rational number.

#### B. [tex]\(\sqrt{12}\)[/tex]
[tex]\[ \sqrt{12} \times \frac{1}{4} = \sqrt{12} \cdot \frac{1}{4} = \frac{\sqrt{12}}{4} = \frac{\sqrt{4 \cdot 3}}{4} = \frac{2\sqrt{3}}{4} = \frac{\sqrt{3}}{2} \][/tex]
[tex]\(\frac{\sqrt{3}}{2}\)[/tex] is irrational because [tex]\(\sqrt{3}\)[/tex] is an irrational number and dividing an irrational number by a rational number still results in an irrational number.

#### C. [tex]\(-\sqrt{36}\)[/tex]
[tex]\[ -\sqrt{36} \times \frac{1}{4} = -\sqrt{36} \cdot \frac{1}{4} = \frac{-\sqrt{36}}{4} = \frac{-6}{4} = -\frac{3}{2} \][/tex]
[tex]\(-\frac{3}{2}\)[/tex] is a rational number.

#### D. [tex]\(0.444444 \ldots\)[/tex]
[tex]\[ 0.444444 \ldots \times \frac{1}{4} = 0.444444 \ldots \cdot \frac{1}{4} = 0.111111 \ldots \][/tex]
[tex]\(0.111111 \ldots\)[/tex] (which is the repeating decimal [tex]\(0.\overline{1}\)[/tex]) is a rational number because it can be expressed as the fraction [tex]\(\frac{1}{9}\)[/tex].

### Conclusion:
The number that, when multiplied by [tex]\(\frac{1}{4}\)[/tex], produces an irrational number is [tex]\(\sqrt{12}\)[/tex] (option B).