Question

Find the angle between the planes 5x + 2y + 3z + 1 = 0 and (1, 1, -2).

(a) 30.82

(b) 3.43

(c) 11.23

(d) 7.54

The question was asked during an online exam.

Question is taken from Three Dimensional Geometry topic in section Three Dimensional Geometry of Mathematics – Class 12

Answer 1

Correct choice is (b) 3.43

The best I can explain: Angle between a plane and a line sin θ=\(\frac {a1a+b1b+c1c}{\sqrt {a^2+b^2+c^2} \sqrt{a1^2+b1^2+c1^2 }}\)

sinθ = 0.06

θ = 3.43