Question

Let two planes P₁ : 2x – y + z = 2 and P₂ : x + 2y – z = 3 are given.

The equation of the acute angle bisector of planes P₁ and P₂ is 

(A) x –  3y + 2z + 1 = 0 

(B) 3x + 3y – 2z + 1 = 0 

(C) x + 3y – 2z + 1 = 0 

(D) 3x + y = 5

Answer 1

Correct option: (A) x – 3y + 2z + 1 = 0

Explanation: 

The given planes can be written as – 2x + y – z + 2 = 0 and –x – 2y + z + 3 = 0

Here (–2) (–1) + (1) (–2) + (–1) (1) = –1 < 0

Equation of bisectors