Question

13. The planes 2x – y + 4z = 5 and 5x – 2.5y + 10z = 6 are
(A) Intersect y-axis
(B) Parallel to each other
(C) Perpendicular to each other
(D) Pass through (0, 0, 5/4)

Answer 1

Answer:

The angle between the planes can be found out by the angle between their normals

Normal of plane 1 2i -j +4k

Normal of plane 2 5i-2.5j+10k

(2i-j-4k)(5i-2.5j+10k)= √4+1+16 × √25+6.25+100 cosФ

cosФ=1

Ф=0°

Therefore both the planes are parallel to each other.