Question

If l,m,n and a,b,c are direction cosines of two lines then

• A. they are parallel when la + mb + nc = 0
• B. they are perpendicular when $\frac{l}{a}=\frac{m}{b}=\frac{n}{c}$
• C. the direction ratios of the bisectors of the angles between l±a, m±b, n±c
• D. the direction ratios of the bisectors of the angles between l±a, m±b, n±c

Answer 1

Answer: (C)

the direction ratios of the bisectors of the angles between l±a, m±b, n±c

Answer 2

The correct option is: (C) the direction ratios of the bisectors of the angles between l±a, m±b, n±c