On 9 mayo, 02:00, Antonio González <gonfe...***gmail.com> wrote:
> tymy escribió:
>
> > calcular la razon en que estan x ***e y ***en ***15(x^2 -y^2) =7xy
>
> Si
>
> *** y/x = tg(t)
>
> queda
>
> *** 15(1-tg^2(t)) = 7 tg(t)
>
> multiplicando por cos^2(t)
>
> *** ***15 cos(2t) = (7/2)sen(2t)
>
> de donde
>
> *** tg(2t) = 30/7
>
> *** t = (1/2)arctg(30/7)
>
> *** y/x = tg(t) = tg(arctg(30/7)/2)
>
> --
>
> *** ***Antonio

se reduce a r*2 - (7/15)r - 1 = 0 con r= x/y