In the following cases, determine whether the given planes are parallel or perpendicular, and in case they are neither, find the angles between them.

4x + 8y + z – 8 = 0 and y + z – 4 = 0

The eq. of the given planes are

4x + 8y + z – 8 = 0 and y + z – 4 = 0


Two planes are if the direction ratio of the normal to the plane is


a1a2 + b1b2 + c1c2 = 0


0 + 8 + 1


9 ≠ 0


Both the planes are not to each other.


Two planes are || to each other if the direction ratio of the normal to the plane is




Both the planes are not || to each other.


The angle between them is given by







= 450


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