since the lines pass through (-2,-9), we have by the point-slope form:

....................(1)

the lines will be of the above form. it is left for us to now find m

since the lines touch the parabola , we have:

by the quadratic formula

now, the thing about tangent lines, is that they touch the curve at one point, that is, we need to ensure that the above quadratic has one solution. to ensure this, we need the discriminant to be zero, hence we must solve

and

plugging these values for m into (1), we find that the lines are:

and