Q83 / 200 · Manipal (MET) 2011 · Mathematics
The equation of plane passing through a point $A$ $(2,-1,3)$ and parallel to the vectors $\mathbf{a}=(3,0,-1)$ and $\mathbf{b}=(-3,2,2)$ is
- A$2 x-3 y+6 z+25=0$
- B$3 x-2 y+6 z+25=0$
- Correct answerC$2 x-3 y+6 z-25=0$
- D$3 x-2 y+6 z-25=0$
Solution
Since, plane is parallel to a given vector, it implies that normal of plane must perpendicular to the given vectors. Given point to which plane passes through is $(2,-1,3)$. Let $A, B$ and $C$ are direction ratios of its normal.
$\therefore$ Equation of plane is
$A(x-2)+B(y+1)+C(z-3)=0$
Now, normal to plane $A \mathbf{i}+B \mathbf{j}+C \mathbf{k}$ is perpendicular to the given vectors
and $\quad \begin{aligned} & \mathbf{a}=3 \mathbf{i}+0 \mathbf{j}-\mathbf{k} \\ & \mathbf{b}=-3 \mathbf{i}+2 \mathbf{j}+2 \mathbf{k}\end{aligned}$
$\therefore \quad 3 A+0 B-C=0$..(i)
and $\quad-3 A+2 B+2 C=0$..(ii)
From Eqs. (i) and (ii), we get
$\frac{A}{2}=\frac{B}{-3}=\frac{C}{6}$
$\therefore$ Equation of plane be
$\begin{array}{ll} & 2(x-2)-3(y+1)+6(z-3)=0 \\ \text { i.e., } \quad & 2 x-3 y+6 z-25=0\end{array}$
Hence, the correct answer is option: 'C'.