Page 99 - Excel for Scientists and Engineers: Numerical Methods

76 EXCEL: NUMERICAL METHODS

4. Return to step 2.
Use this method to calculate the square root of a number. The value of the
initial estimate x must be greater than zero.

9. In the divide-and-average method, the better the initial estimate, the faster the
convergence. Devise an Excel formula to provide an effective initial
estimate.

10. The series
16(-lk+') 4(-Ik+')
-5 (2k - 1)2392k-'

proposed by Machin in 1706, converges quickly. Determine the value of x to
15 digits by using this series