Question

The distance of the point $P(a,b,c)$ from the $x$-axis is

• A. $\sqrt{b^2+c^2}$
• B. $\sqrt{a^2+c^2}$
• C. $\sqrt{a^2+b^2}$
• D. None of these

Answer 1

Answer: (A)

The coordinates of the foot of the perpendicular from $P$ on $x$-axis are ($a$, $0,0$). Therefore, the required distance is
$\sqrt{{\left(a-a\right)}^2+{\left(b-0\right)}^2+{\left(c-0\right)}^2}$
$=\sqrt{b^2+c^2}$.