Question

Using square root table, find the square root 

Answer 1

We have to find 

\[\sqrt{21 . 97}\]

From the square root table, we have:

\[\sqrt{21} = \sqrt{3} \times \sqrt{7} = 4 . 583 \text{ and } \sqrt{22} = \sqrt{2} \times \sqrt{11}\]  

Their difference is 0.107.
Thus, for the difference of 1 (22 \[-\] 21), the difference in the values of the square roots is 0.107.
For the difference of 0.97, the difference in the values of their square roots is: \[0 . 107 \times 0 . 97 = 0 . 104\] 

\[\therefore\] \[\sqrt{21 . 97} = 4 . 583 + 0 . 104 \approx 4 . 687\]