note: me intrepret yer "acos" tu meen a* kosine, not the invers kosine... 1. x=a*kosine^2(t)... 2. y=a*sine(t)... so x+y^2=(a*sine^2+a^2*sine^2(t))... so ax+y^2=a^2*(sine^2+kosine^2)=a^2... or y^2=a^2 -ax... or y=root(a^2-ax)=root(a)*root(a-x) a parabola with horizontal axis...perhaps a dubel pare av parabolas