If x1, x2, x3 and y1, y2, y3 are in G.P ,where common ratio is r, then point P (x1,y1), Q (x2,y2), R (x3,y3) are on.
a straight line
an ellipse
a circle
Vertices of a triangle
x - y = -5
If the lines 2 x + 3 a y - 1 = 0 and 3 x + 4 y + 1 = 0 are mutually perpendicular , then a =
2
-1/2
1/2
1
4
