X root Operator help

lucidparadox dwcoll01 at gmail.com
Wed Apr 18 16:28:15 CEST 2007


On Apr 18, 8:52 am, Michael Hoffman <cam.ac... at mh391.invalid> wrote:
> lucidparadox wrote:
> > I'm currently new to Python and I haven't been able to find the
> > operator/math function to find the square root or even the x root of a
> > number.
>
> For square root, use math.sqrt(y)
>
> For x root use y**(1/x)
>
>  > I'm rewriting a program that I wrote in BASIC that does the
>  > math of a quadratic equation (user puts in a, b, and c values) and
>  > tells the user whether it has 1 root, 2 roots, or no real roots and
>  > displays the roots if it has real roots.
>
> In floating point arithmetic, the naive way of calculating both roots
> always using the formula (-b +/- sqrt(b**2 - 4*a*c))/2*a will give you
> inaccurate results sometimes. See
> <http://www.cse.uiuc.edu/eot/modules/floating_point/quadratic_formula/>.
>
> For a better formula, see how r_1 and r_2 are defined in
> <http://en.wikipedia.org/wiki/Quadratic_equation#Alternative_formula>.
> --
> Michael Hoffman

Thanks.  As of right now I'm just trying to familiarize myself with
the syntax of Python.  Actually I should have thought of y**(1/x).
I'm currently a freshman in college so the alternative formula hasn't
been introduced to me yet.  Thanks for the pointers though.

Dan Collins




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