An irrational number, d , has a value such that 6<d<7. Which of the following is a possible value for ?

A.
square root of 6.2
B.


C.
square root of 13
D.

1 answer

To determine which of the given options can be a possible irrational number \( d \) such that \( 6 < d < 7 \), let's evaluate each option.

A. \( \sqrt{6.2} \)

To approximate \( \sqrt{6.2} \), consider the squares:

  • \( \sqrt{6} \approx 2.449 \) (since \( 2.449^2 \approx 6 \))
  • \( \sqrt{7} \approx 2.646 \) (since \( 2.646^2 \approx 7 \))

Calculating \( \sqrt{6.2} \):

Using a calculator, \( \sqrt{6.2} \approx 2.489 \).

Thus, \( \sqrt{6.2} \approx \) 2.489 is not relevant since it is not in the range \( 6 < d < 7 \).

B. \( 2\pi \)

Approximating \( 2\pi \):

\[ 2\pi \approx 2 \times 3.14 \approx 6.28 \]

This value \( 6.28 \) lies in the interval \( (6, 7) \), so \( 2\pi \) is a possible value.

C. \( \sqrt{13} \)

To approximate \( \sqrt{13} \):

Calculating \( 3.6^2 = 12.96 \) and \( 3.7^2 = 13.69 \).

Thus, \( \sqrt{13} \) is approximately \( 3.605 \), which does not lie within \( (6, 7) \).

D. \( 6\pi \)

Calculating \( 6\pi \):

\[ 6\pi \approx 6 \times 3.14 \approx 18.84 \]

This value is far outside the range \( (6, 7) \).

From the options, only option B \( 2\pi \) satisfies the condition \( 6 < d < 7 \).

Thus, the possible value for \( d \) is:

Answer: B. \( 2\pi \)