The perpendicular distance of the point P(3, 3, 4) from the x-axis is
Given: point P(3, 3, 4)
To find: length of the perpendicular drawn from the point P from the x-axis
Formula used:
The distance between any two points (a, b, c) and (m, n, o) is given by,
As, y and z coordinate on x-axis are zero
Let point D on x-axis is (x, 0, 0)
Direction cosines of z-axis are (1, 0, 0)
Direction cosines of PD are (3 – x, 3 – 0, 4 – 0) = (3 – x, 3, 4)
Let are two vectors as shown in the figure:
The dot product of perpendicular vectors is always zero
Therefore,
⇒ (3 – x) × 1 + 3 × 0 + 4 × 0 = 0
⇒ 3 – x + 0 + 0 = 0
⇒ x = 3
Hence point D(3, 0, 0)
Distance between point P(3, 3, 4) and D(3, 0, 0) is d
= 5
Hence, the distance of the point P from x-axis is 5 units