Question

If the length of perpendicular drawn from origin on a plane is 7 units and its direction ratios are –3, 2, 6, then that plane is

• A. $- 3x + 2y + 6z - 7 = 0$
• B. $- 3x + 2y + 6z - 49 = 0$
• C. $3x - 2y + 6z + 7 = 0$
• D. $- 3x + 2y - 6z - 49 = 0$

Answer 1

Answer: (B)

$- 3x + 2y + 6z - 49 = 0$

Answer 2

Equation of a plane, when direction ratio and length of perpendicular is given, $a x + b y + c z = p \sqrt { a ^ { 2 } + b ^ { 2 } + c ^ { 2 } }$

Given, $( a , b , c ) \rightarrow ( - 3,2,6 )$

$- 3 x + 2 y + 6 z = 7 \sqrt { ( - 3 ) ^ { 2 } + 2 ^ { 2 } + 6 ^ { 2 } }$

$- 3 x + 2 y + 6 z = 49$.