Home › JEE Advanced › Mathematics › Surface Areas and Volumes › Two lines with direction ratios $(a_1,b_1,c_1)$ …
Two lines with direction ratios $(a_1,b_1,c_1)$ and $(a_2,b_2,c_2)$ are perpendicular if:
A$a_1a_2+b_1b_2+c_1c_2=0$
B$a_1a_2+b_1b_2+c_1c_2=1$
C$\tfrac{a_1}{a_2}=\tfrac{b_1}{b_2}=\tfrac{c_1}{c_2}$
D$a_1+a_2=b_1+b_2$
Answer & Solution
Correct answer: A. $a_1a_2+b_1b_2+c_1c_2=0$
Lines are perpendicular when the sum of products of their direction ratios is zero: a₁a₂+b₁b₂+c₁c₂=0.
Related questions
Painting the outside of a toy needs to be worked out from its:Breaking a hard problem into solved smaller ones is the method:A cylindrical tube with a rounded end is a cylinder with a:Pouring a liquid into a container of another shape keeps its:Joining two solids at their flat faces hides those faces:Which solid is not among the basic ones met earlier?The word frustum comes from Latin, meaning a piece:The two circular ends of a frustum have radii that are: