Respuesta :
IF the equation is y=−1/12x^2−2x−1
then -12y=x^2+24x+12
-12y+132=x^2+24x+144
-12(y-11)=(x+12)^2
so the vertex of the parabola is at (-12, 11)
semi axis length=12/4=3
the focus is at (-12, 11-3) = (-12, 8)
using a graphing calculator, u can plot y=−112x2−2x−1
it is a concave parabola with focus at approx. (-0.0089, -0.9933)
it is a concave parabola with focus at approx. (-0.0089, -0.9933)