To find a rational number with a denominator of 7 that lies between \(7 - \sqrt{7}\) and \(8 - \sqrt{8}\), we will first determine the approximate values of these expressions.
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Calculate \(7 - \sqrt{7}\):
- \(\sqrt{7} \approx 2.6457513110645906\)
- Therefore, \(7 - \sqrt{7} \approx 7 - 2.6457513110645906 \approx 4.3542486889354094\).
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Calculate \(8 - \sqrt{8}\):
- \(\sqrt{8} = 2\sqrt{2} \approx 2.8284271247461903\)
- Therefore, \(8 - \sqrt{8} \approx 8 - 2.8284271247461903 \approx 5.17157287525381\).
This gives us the bounds:
- Lower bound: \(4.3542486889354094\)
- Upper bound: \(5.17157287525381\)
Now, we need to find a rational number with a denominator of 7 in this range. A rational number with a denominator of 7 can be represented as \(\frac{n}{7}\), where \(n\) is an integer.
To find suitable values for \(n\), we will multiply the bounds by 7:
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For the lower bound: \[ 4.3542486889354094 \times 7 \approx 30.481741822548866 \quad \text{(rounding this gives us 30 or 31)} \]
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For the upper bound: \[ 5.17157287525381 \times 7 \approx 36.201010126777677 \quad \text{(rounding this gives us 36 or 37)} \]
Now we need integer values of \(n\) that are within the range 30 to 36.
Checking whole numbers in that range:
- \(n = 31: \frac{31}{7} \approx 4.428571428571429\)
- \(n = 32: \frac{32}{7} \approx 4.571428571428571\)
- \(n = 33: \frac{33}{7} \approx 4.714285714285714\)
- \(n = 34: \frac{34}{7} \approx 4.857142857142857\)
- \(n = 35: \frac{35}{7} \approx 5.0\)
All of these \(n\) values yield rational numbers between \(7 - \sqrt{7}\) and \(8 - \sqrt{8}\):
- \(\frac{31}{7} \approx 4.43\) (between \(4.354\) and \(5.171\))
- \(\frac{32}{7} \approx 4.57\) (between \(4.354\) and \(5.171\))
- \(\frac{33}{7} \approx 4.71\) (between \(4.354\) and \(5.171\))
- \(\frac{34}{7} \approx 4.86\) (between \(4.354\) and \(5.171\))
- \(\frac{35}{7} = 5.0\) (also between \(4.354\) and \(5.171\))
Thus, any of the following rational numbers fit the criteria:
- \(\frac{31}{7}, \frac{32}{7}, \frac{33}{7}, \frac{34}{7}, \frac{35}{7}\).
A specific example is: \[ \frac{33}{7} \] This value is between \(7 - \sqrt{7}\) and \(8 - \sqrt{8}\).