Direction ratios of two lines satisfy the relations `2a-b+2c=0` and `ab+bc+ca=0`. Then the angle between two lines is

The direction ratios of two lines satisfy the relation 2a - b + 2c = 0 and ab + bc + ca = 0 . Show that the lines are perpendicular.

If the direction ratios of two lines are given by a + 2b + c = 0 and 11 bc +6ca - 14 ab = 0 . then the angle between these lines is

If the direction ratio of two vectors are connected by the relations a+b+c=0 and a^(2)+b^(2)=c^(2). then the angle between two vectors

If the direction rations of two lines are given by 3lm-4ln+mn = 0 and l + 2m + 3n = 0 then the angle between the lines is

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

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 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 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