CompuServe Messages

Jack, thank you for your reply. I've pretty much decided that the best way to do this is with Newton's method. The problem with this has been coming up with a good initial guess. With large numbers, it can take up to 13 iterations for a evaluation correct to 4 decimal places The problem with lookup tables or interpolation is that the square root function is not linear and you get greater errors as you look for the square roots of larger numbers. The only solution to this is to create a table of increasing density. This is my solution to the problem. Using a table of known square roots, interpolating to a close answer is easy. I then use this number as my initial guess in solving for the square root by Newton's method. This produces accurate values in only 2 – 4 iterations. Another method for anyone who already was a natural log function and a EXPonent function is the equation: x^2 – (value) = 0 ln(x^2) = ln(value) ( x = sqr(value) ) 2ln(x) = constant – look up in table x = exp(constant/2)…outa room..thanks….kirk