The line x = k intersects the graph of the parabola x = -2y^2 - 8y + 5 at exactly one point. What is k?
+36916 For a line x=k (a vertical line) to intersect a horizontal parabola at only one point, that point must be the vertex....do you know how to find the vertex?
+36916 -2 (y2 +4y) + 5
x = -2 (y+2)2 +13
this is a sideways parabola of the form x = a(y-k)2 +h The vertex is 13,-2
so the line x = k = 13 will touch in only one point
