Questions: Which of the following is a rational number? The square root of 9 The square root of 2 The square root of 20 The square root of 15
Transcript text: Which of the following is a rational number? The square root of 9 The square root of 2 The square root of 20 The square root of 15
Solution
Solution Steps
To determine which of the given options is a rational number, we need to check if the square root of each number is a whole number. A rational number can be expressed as a fraction of two integers, and whole numbers are a subset of rational numbers. Therefore, we will calculate the square root of each number and check if it is an integer.
Step 1: Identify the Nature of Each Square Root
To determine which of the given numbers has a rational square root, we calculate the square root of each number: \( \sqrt{9} \), \( \sqrt{2} \), \( \sqrt{20} \), and \( \sqrt{15} \).
Step 2: Calculate the Square Roots
\( \sqrt{9} = 3 \)
\( \sqrt{2} \approx 1.414 \)
\( \sqrt{20} \approx 4.472 \)
\( \sqrt{15} \approx 3.873 \)
Step 3: Determine Rationality
A number is rational if it can be expressed as a fraction of two integers. In this context, a square root is rational if it results in a whole number. From the calculations:
\( \sqrt{9} = 3 \) is a whole number.
\( \sqrt{2} \), \( \sqrt{20} \), and \( \sqrt{15} \) are not whole numbers.