Question

The length of perpendicular from the point $(7,14,5)$ to the plane $2x+4y-z=2$ is

• A. $21\sqrt{3}$
• B. $3\sqrt{21}$
• C. $\sqrt{321}$
• D. $5\sqrt{2}$

Answer 1

Answer: (B)

$3\sqrt{21}$

Length of perpendicular $=\frac{\left|2\left(7\right)+4\left(14\right)-5-2\right|}{\sqrt{21}}$

$\begin{array}{c}=\frac{63}{\sqrt{21}}\\ =3\sqrt{21}\end{array}$

Hence,

Option $B$ is correct answer.