Supose directioncoisnes of two lines are given by `u l+vm+wn=0 and al^2+bm^2+cn^2=0` where u,v,w,a,b,c are arbitrary constnts and l,m,n are directioncosines of the lines. For `u=v=w=1` directionc isines of both lines satisfy the relation. (A) `(b+c)(n/l)^2+2b(n/l)+(a+b)=0` (B) `(c+a)(l/m)^2+2c(l/m)+(b+c)=0` (C) `(a+b)(m/n)^2+2a(m/n)+(c+a)=0` (D) all of the above

Supose directioncoisnes of two lines are given by u l+vm+wn=0 and al^2+bm^2+cn^2=0 where u,v,w,a,b,c are arbitrary constnts and l,m,n are directioncosines of the lines. For u=v=w=1 if lines are perpendicular then. (A) a+b+c=0 (B) ab+bc+ca=0 (C) ab+bc+ca=3abc (D) ab+bc+ca=abc

The direction cosines of two lines are related by l+m+n=0 and al^(2)+bm^(2)+cn^(2)=0 The linesare parallel if

Supose directioncoisnes of two lines are given by u l+vm+wn=0 and al^2+bm^2+cn^2=0 where u,v,w,a,b,c are arbitrary constnts and l,m,n are directioncosines of the lines. For u=v=w=1 if (n_1 n_2)/(l_1 l_2)=((a+b)/(b+c)) then (A) (m_1m_2)/(l_1 l_2)=((b+c))/((c+a)) (B) (m_1m_2)/(l_1 l_2)=((c+a))/((b+c)) (C) (m_1m_2)/(l_1 l_2)=((a+b))/((c+a)) (D) (m_1m_2)/(l_1 l_2)=((c+a))/((a+b))

The acute angle between the two lines whose d.cs are given by l+m-n=0 and l^(2)+m^(2)-n^(2)=0 is

If l_(1), m_(1), n_(1) and l_(2), m_(2), n_(2) are the direction cosines of two lines and l , m, n are the direction cosines of a line perpendicular to the given two lines, then

the acute angle between two lines such that the direction cosines 1,m,n of each of them satisfy the equations l+m+n=0 and l^(2)+m^(2)-n^(2)=0 is