Which one? Circle: + and no a or b OR a=b Ellipse: + and =1 and a=b Hyperbola: - and = 1 Parabola: only 1 sqaured variable

02-4(1)(2) = -8 and b=0, 1=1 so circle 3y2 – x2 – 9 = 0   Parabola Hyperbola Ellipse Circle b2-4ac =0 Parabola >0 Hyperbola < 0 b =0 b =0 Determine the conic: 6x2 + 9y2 + 12x – 15y – 25 = 0  02-4(6)(9) = -216 and b=0, 6=9 so ellipse x2 + y2 – 6x – 7 = 0  02-4(1)(2) = -8 and b=0, 1=1 so circle 3y2 – x2 – 9 = 0   02-4(-1)(3) = 12 OR minus sign for one squared term so hyperbola y2 – 2x – 4y + 10 = 0  02-4(0)(1) = 0 OR only 1 squared term so parabola a = c a = c Ellipse Circle

PREAP A parabolic reflector is in the shape made by revolving an arc of a parabola, starting at the vertex, about the axis of the parabola. If the focus is 9 inches from the vertex, and the parabolic arc is 16 inches deep, how wide is the opening of the reflector?       The face of a one-lane tunnel is a square with a semi-circle above it. The semi-circle has a diameter of 18 ft. A truck that is 15 ft wide and 22 ft tall tries to drive through the tunnel. Will the truck fit? By how much? (over or under)