For the lines `L_1 ; vec a+t(vec b+vec c) and L_2 ; vec r=vec b+s(vec c+vec a)` then `L_1 and L_2` 1ntersect at

For the lines L_(1);vec a+t(vec b+vec c) and L_(2);vec r=vec b+s(vec c+vec a) then L_(1) and L_(2) ntersect at

If the lines vec r = vec a + lambda (vec b xx vec c) and vec r = vec b + mu (vec c xx vec a) are intersect then ...............

If the lines vec r=x((vec b)/(|vec b|)+(vec c)/(|vec c|)) and vec r=2vec b+y(vec c-vec b) intersect at a point with position vector z((vec b)/(|vec b|)+(vec c)/(|vec c|)), then

If the lines vec r=x((vec b)/(|vec b|)+(vec c)/(|vec c|)) and vec r=2vec b+y(vec c-vec b) intersect at a point with position vector z((vec b)/(|vec b|)+(vec c)/(|vec c|)), then

[vec a+vec b,vec b+vec c,vec c+vec a]=2[vec a,vec b,vec c]

[vec a + vec b, vec b + vec r * vec cvec c + vec a] = 2 [vec with bvec c]

[vec a + vec b, vec b + vec c, vec c + vec a] = 2 [vec a, vec b, vec c]

Write a vector normal to the plane vec r=l vec b+m vec c

Write a vector normal to the plane vec r=l vec b+m vec c

If vec a, vec b, vec c are three vectors such that vec a . (vec b + vec c) + vec b . (vec c + vec a) + vec c . (vec a + vec b) = 0 and |vec a| = 1, |vec b | = 4, |vec c| = 8 , then |vec a + vec b + vec c| =