Question:
Let $P$ be the plane passing through the point $(1,2,3)$ and the line of intersection of the planes
$\overrightarrow{\mathrm{r}} \cdot(\hat{\mathrm{i}}+\hat{\mathrm{j}}+4 \hat{\mathrm{k}})=16$ and $\overrightarrow{\mathrm{r}} \cdot(-\hat{\mathrm{i}}+\hat{\mathrm{j}}+\hat{\mathrm{k}})=6 .$ Then
which of the following points does NOT lie on P?
Correct Option: , 3
Solution:
$(x+y+4 z-16)+\lambda(-x+y+z-6)=0$
Passes through $(1,2,3)$
$-1+\lambda(-2) \Rightarrow \lambda=-\frac{1}{2}$
$2(x+y+4 z-16)-(-x+y+z-6)=0$
$3 x+y+7 z-26=0$