Find the direction cosines of the lines, connected by the relations: `l+m+n=0` and `2l m+2ln-m n=0.`

Find the direction cosines of the two lines which are connected by th relations.l-5m+3n=0 and 7l^(2)+5m^(2)-3n^(2)=0

Find the angle between the lines whose direction cosines are connected by the relations l+m+n=0and2lm+2nl-mn=0

If the direction cosines of two lines are connected by the equations l+m+n=0 and l^(2) + m^(2) -n^(2)=0 , then the angle between these lines is of measure

Find the direction cosines l + m + n of the two lines which are connected by the relation l+ m + n = 0 and mn – 2nl –2lm = 0.

The direction cosines l, m and n of two lines are connected by the relations l+m+n=0 and lm=0 , then the angle between the lines is

The direction cosines of two lines are connected by relation l+m+n=0 and 4l is the harmonic mean between m and n. Then,

If (theta) is an angle between two lines whose direction cosines are connected by the relations l-5m+3n=0 and 7l^(2)+5m^(2)-3n^(2)=0 then 12cos^(2)theta =