The vector equation of line passing through (2, -1, 3) and perpendicular to the lines $\frac{x-2}{3}=\frac{y-1}{1}=\frac{z+2}{2}$ and $\frac{x+3}{-4}=\frac{y-5}{-3}=\frac{z+1}{2}$ is (Here $λ$ is a parameter) |
$\vec r= (2\hat i-\hat j+3\hat k) +λ (8\hat i-14\hat j-5\hat k)$ $\vec r= (-2\hat i+\hat j-3\hat k) +λ (8\hat i-14\hat j-5\hat k)$ $\vec r= (-8\hat i-14\hat j-5\hat k) +λ (-2\hat i+\hat j+3\hat k)$ $\vec r= (8\hat i-14\hat j-5\hat k) +λ (2\hat i-\hat j+3\hat k)$ |
$\vec r= (2\hat i-\hat j+3\hat k) +λ (8\hat i-14\hat j-5\hat k)$ |
The correct answer is Option (1) → $\vec r= (2\hat i-\hat j+3\hat k) +λ (8\hat i-14\hat j-5\hat k)$ Given lines in symmetric form: $\frac{x-2}{3}=\frac{y-1}{1}=\frac{z+2}{2}\;\Rightarrow\;$ direction $\vec{v}_{1}=\langle 3,1,2\rangle$ $\frac{x+3}{-4}=\frac{y-5}{-3}=\frac{z+1}{2}\;\Rightarrow\;$ direction $\vec{v}_{2}=\langle -4,-3,2\rangle$ Required line ⟂ to both ⇒ direction $\vec{v}=\vec{v}_{1}\times\vec{v}_{2}$ $\vec{v}=\begin{vmatrix}\hat{i}&\hat{j}&\hat{k}\\3&1&2\\-4&-3&2\end{vmatrix} =8\hat{i}-14\hat{j}-5\hat{k}$ Passing through $(2,-1,3)$: $\vec{r}=(2\hat{i}-\hat{j}+3\hat{k})+\lambda\,(8\hat{i}-14\hat{j}-5\hat{k})$ |