Question
Question: The plane 2x – 3y + 6z – 11 = 0 makes an angle sin<sup>–1</sup>(1) with the x-axis. Then the value o...
The plane 2x – 3y + 6z – 11 = 0 makes an angle sin–1(1) with the x-axis. Then the value of 'a' is :
A
23
B
32
C
73
D
72
Answer
72
Explanation
Solution
Q DR's of the normal of the plane Ž 2, –3, 6
& DR's of x-axis is 1, 0, 0
& If 'q' is the angle between the plane
& x-axis, then sin q = 22+(–3)2+6212(1)+(–3)(0)+(6)(0)= 72
Ž q = sin–1(72)
\ a = 72