Q1. Condition that the cone ax2 + by2 + cz2 + 2fyz + 2gzx + 2hxy = 0 may have three mutually perpendicular generating lines, is
- (1) (1)/(a) + (1)/(b) + (1)/(c) = 0
- (2) a+b+c=0
- (3) af+bg+ch=0
- (4) (a)/(f) + (b)/(g) + (c)/(h) = 0
- (5) Question not attempted