Home › JEE Main › Mathematics › Surface Areas and Volumes › Angle θ between two planes 2x + 3y + 4z = 0 and …
Angle θ between two planes 2x + 3y + 4z = 0 and x + y + z = 0:
Acos θ = 9/sqrt(29 × 3) = 9/sqrt(87)
B90°
C45°
D0
Answer & Solution
Correct answer: A. cos θ = 9/sqrt(29 × 3) = 9/sqrt(87)
Normals: (2,3,4) and (1,1,1). cos θ = (2+3+4)/sqrt(4+9+16)sqrt(1+1+1) = 9/sqrt(29)sqrt(3) = 9/sqrt(87) ≈ 0.965. θ ≈ 15.2°.
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: