[" The two lines "ax+by=c" and "a'x+b'y=c'" are perpendicular if "],[[aa'+bb'=0],[ab'=ba']],[" ab "+a'b'=0]

The two lines ax+by=cand a'x+b'y=c' are perpendicular if

The two lines ax+by+c=0 and a'x+b'y+c'=0 are perpendicular if (i) ab'=a'b (ii) ab+a'b'=0 (iii) ab'+a'b=0 (iv) a a'+b b'=0

If planes ax+by+cz+d=0 and a'x+b'y+c'z+d'=0 are perpendicular, then

the two lines x=ay+b,z=cy+d and x=a\'y+b,z=c\'y+d\' will be perpendicular, if and only if: (A) aa\'+cc\'=1=0 (B) aa\'+bb\'+cc\'=1=0 (C) aa\'+bb\'+cc\'=0 (D) (a+a\')+(b+b\')+(c+c\')=0

If the quadrilateral formed by the lines ax+by+cz=0, ax+b'y+c=0, a'x+by+c'=0, a'x+b'y+c'=0 have perpendicular diagonals, then :

If ax+by+c=0 " and " a'x+b'y+c'=0 , then prove that x/(bc'-b'c)=y/(ca'-c'a)=1/(ab'-a'b)

If the quadrilateral formed by the lines ax+by+c=0. a'x+b'y+c=0, ax+by+c'=0, a'x+b'y+c'=0 has perpendicular diagonal, then