On Sun, Nov 23, 2008 at 9:44 AM, David <[EMAIL PROTECTED]> wrote: > The working code: > > a = 2; b = 1; c = 2 > import math > q = math.sqrt(math.fabs(b*b - 4*a*c)) > x1 = (-b + q)/2*a > x2 = (-b - q)/2*a > print x1, x2
Working in the sense of "completes without an error message and prints a result", anyway. Not working in the sense of "gives the correct answer". Using your code above gives In [17]: print x1, x2 2.87298334621 -4.87298334621 In [18]: a*x1*x1 + b*x1 + c Out[18]: 21.381049961377752 which should be 0. Some quadratic equations do not have a solution in the real numbers, only in complex numbers. You might want to look at cmath.sqrt() which will take the square root of a negative number, giving a complex result. Using the above values for a, b, c: In [19]: import cmath In [20]: cmath.sqrt(b*b - 4*a*c) Out[20]: 3.872983346207417j Kent _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
