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`

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 (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))

If the lines ax+by+c=0, bx+cy+a=0 and cx+ay+b=0 (a, b,c being distinct) are concurrent, then (A) a+b+c=0 (B) a+b+c=1 (C) ab+bc+ca=1 (D) ab+bc+ca=0

The dr's of two lines are given by a+b+c=0,2ab +2ac-bc=0 . Then the angle between the lines is

If a + b- c = 4 and a^(2) + b^(2) + c^(2)= 38 , find ab- bc - ca

If a^2+b^2+c^2=1 then ab+bc+ca lies in the interval

If a + b + c= 12 and a^(2) + b^(2) + c^(2) = 50 , find ab + bc + ca

If a+b+c = 10 and a^(2) + b^(2) + c^(2) = 38 , find : ab + bc + ca

Find : a^(2) + b^(2) + c^(2) , if a+ b+ c = 9 and ab+ bc + ca = 24

If a+b+ c=9 and ab + bc +ca = 15 , find : a^2 + b^2 + c^2 .