MathematicsEasy249×since 2002Q2368The two lines x=ay+b,z=cy+dx=ay+b,z=cy+dx=ay+b,z=cy+d and x=a′y+b′,z=c′y+d′x = a'y + b',z = c'y + d'x=a′y+b′,z=c′y+d′ will be perpendicular, if and only if :Aaa′+cc′+1=0aa' + cc' + 1 = 0aa′+cc′+1=0Baa′+bb′cc′+1=0aa' + bb'cc' + 1 = 0aa′+bb′cc′+1=0Caa′+bb′cc′=0aa' + bb'cc' = 0aa′+bb′cc′=0D(a+a′)(b+b′)+(c+c′)=0\left( {a + a'} \right)\left( {b + b'} \right) + \left( {c + c'} \right) = 0(a+a′)(b+b′)+(c+c′)=0Check answerSkip