Using a number line, what whole number and rational number to the nearest half is square root 105 between?

1 answer

To find between which whole number and rational number (to the nearest half) the square root of 105 falls, we first need to calculate the approximate value of √105.

We know that:

  • \(10^2 = 100\)
  • \(11^2 = 121\)

So, \(10 < \sqrt{105} < 11\).

Next, we approximate √105. We can refine our estimate by calculating:

\[ 10.2^2 = 104.04 \] \[ 10.3^2 = 106.09 \]

Since \(10.2^2\) is less than 105 and \(10.3^2\) is greater than 105, we can conclude:

\[ 10.2 < \sqrt{105} < 10.3 \]

Next, we check if √105 is closer to 10 or to 10.5. Since:

\[ 10.25^2 = 105.0625 \]

and since 105 is closer to 105.0625 than it is to 104.04, we can further narrow this down.

Thus, the square root of 105 is approximately:

\[ \sqrt{105} \approx 10.246 \]

Now let's address the question of rational numbers to the nearest half. The nearest halves to consider around 10.246 are 10.0 and 10.5.

Therefore, we can conclude that:

  • The whole number between which √105 lies is 10.
  • The nearest half (rational number) is 10.5.

So, summarizing: √105 is between 10 and 10.5.