Question

Find the coordinates of the foot of the perpendicular drawn from the origin to the plane $5y+8=0$

• A. $(0,-\frac{18}{5},2)$
• B. $(0,\frac{8}{5},0)$
• C. $(\frac{8}{25},0,0)$
• D. $(0,-\frac{8}{5},0)$

Answer 1

The correct option is D $(0,-\frac{8}{5},0)$

$5y+8=0$
$\Rightarrow y=-\frac{8}{5}$
This represents a plane parallel to $xz$-plane which cuts negative y-axis at a distance of $\frac{8}{5}$ units from the origin.
$\therefore$ Required coordinate is $(0,-\frac{8}{5},0)$