Show that the planes 3x + 4y – 5z + 7 = 0 and x + 3y + 3z + 7 = 0 are perpendicular.

Asked by Topperlearning User | 4th Jun, 2014, 01:23: PM

Expert Answer:

The direction ratios of the normals to the planes are 3, 4, – 5 and 1, 3, 3.

Now, (3)(1) + (4)(3) + (– 5)(3) = 3 + 12 – 15 = 15 – 15 = 0.
Therefore, the planes are perpendicular to each other.

Answered by  | 4th Jun, 2014, 03:23: PM