The equation of the directrix of the parabola x2 = -4ay is.
x + a = 0
x - a = 0
y + a = 0
y - a = 0
The equation of the parabola with directrix x = 2 and the axis y = 0 is.
y2 = 8x
y2 = -8x
y2 = 4 x
y2 = -4 x
The tangents at the points (at12 , 2at1), (at22, 2at2) on the parabola y2 = 4ax are at right angles if
t1t2 = -1
t1t2 = 1
t1t2 = 2
t1t2 = -2
The focus of the parabola (y - 2)2 = 20(x + 3) is
A line touches the circle x2 + y2 = 2 a2 and also the parabola y2 = 8 ax.Its equation is.
y = ± x
y = ± ( x + c)
y = ± (x + 2a)
y = ± ( x - 2a)
If the line 3x - 4y + 5 = 0 is a tangent to the parabola y2 = 4ax, then a is equal to
15/16
5/4
-4/3
-5/4
The parabola y2 = 4 ax passes through the point (2, -6) , then the length of its latus rectum is
18
9
6
16
The equation of the parabola with focus at (0, 3) and the directrix y + 3 = 0 is
y2 = 12x
y2 = -12 x
x2 = 12 y
x2 = -12 y
The vertex of the parabola y2 = 4a (x - a) is
(a, 0)
(0, a)
(0, 0)
None of these
The eccentricity of the parabola y2 = -8x is
-2
2
-1
1
