Question

The direction cosines of the normal to the plane $6x-3y-2z=1$ are:

• A. $\left(\frac{6}{7},3,\frac{-2}{7}\right)$
• B. $(6,-3,-2)$
• C. $\frac{1}{7}(6,-3,-2)$
• D. $\frac{1}{7}(6,3,2)$
• E. $\frac{1}{7}(-6,2,3)$

Answer 1

Answer: (C)

Direction cosines of the normal to the plane are $\frac{6}{\sqrt{36+9+4}},\frac{-3}{\sqrt{36+9+4}},\frac{-2}{\sqrt{36+9+4}}$ $\equiv \left(\frac{6}{7},\frac{-3}{7},\frac{-2}{7}\right)$