Q.
If one of the line represented by the equation ax2 + 2hxy + by2 = 0 is coincident if one of the line represented by a′x2 + 2h′xy + b′y2 = 0, then
A. (ab′-a′b)2=4(a′h - a′h)(hb′ - h′b)
(ab′-a′b)2=4(a′h - a′h)(hb′ - h′b)
B. (ab′+a′b)2=4(a′h - a′h)(hb′ - h′b)
(ab′+a′b)2=4(a′h - a′h)(hb′ - h′b)
C. (ab′-a′b)2=(a′h - a′h)(hb′ - h′b)
(ab′-a′b)2=(a′h - a′h)(hb′ - h′b)
D. (ab′-a′b)2=4(a′h + a′h)(hb′ - h′b)
(ab′-a′b)2=4(a′h + a′h)(hb′ - h′b)
E. None of the above
Correct choice: A
Explanation: