Size of errors using approximating functions

The percentage error introduced by calculating the correction factor, bo, using polynomials will be 

Here the pressure ratio, Pj/Pi, follows from equation (A2.14)  

For a horizontal pipe, equation (A2.43) below may be used in place of equations (A2.39) and (A2.40) 

Streeter, V.L., and Wylie, E.B. (1983). Fluid Mechanics, First SI Metric Edition, McGraw-Hill, New York, Chapter 4, Dimensional analysis and dynamic similitude. 

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