Mark against the A.

B.

C.

D.

Given: Equation of two planes are 2x – y + z = 6 and x + y + 2z = 7

To find: Angle between the two planes

Formula Used: Angle between two planes a₁x + b₁y + c₁z = 0 and a₂x + b₂y + c₂z = 0 is

where θ : angle between the planes,

Explanation:

Here a₁ = 2, b₁ = -1, c₁ = 1

a₂ = 1, b₂ = 1, c₂ = 2

Therefore angle between the planes is