tag:blogger.com,1999:blog-264226589944705290.post4015174555949628511..comments2022-11-19T01:08:31.131-08:00Comments on God Plays Dice: The IRS quadratic formulaMichael Lugohttp://www.blogger.com/profile/15671307315028242949noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-264226589944705290.post-28353233227129601762008-02-13T23:36:00.000-08:002008-02-13T23:36:00.000-08:00I guess the moral of it is that there is little va...I guess the moral of it is that there is little value in memorizing a formula (even for a quadratic). Learning how to derive a formula is much more valuable and intellectually stimulating.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-264226589944705290.post-29420970681361262862008-02-13T12:45:00.000-08:002008-02-13T12:45:00.000-08:00The square root form could have been made even big...The square root form could have been made even bigger by using a numerically more robust formula. In the standard formula (-B±√(B^2-4AC))/2A, compute one root x_1 by chosing the sign to match that of -B, then compute the root as x_2=C/Ax_1. This avoids the cancellation effects that could otherwise ruin the accuracy of the smaller root.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-264226589944705290.post-15436750038465250152008-02-11T17:20:00.000-08:002008-02-11T17:20:00.000-08:00If I remember correctly the actual equation for ta...If I remember correctly the actual equation for tax isn't hard once you have the income variable X--it's merely a piecewise defined linear function. It's finding X that's the problem. As for the quartic...<BR/><BR/>http://planetmath.org/encyclopedia/QuarticFormula.html<BR/><BR/>The Galois-theoretic derivation is much easier to understand.Williamhttps://www.blogger.com/profile/11620499500613863262noreply@blogger.com