Question

The equation of the plane through $(-1, 1 , 2 )$ whose normal makes equal acute angles with co-ordinate axes is

• A. $\vec{r} . (\hat{i} + \hat{j} + \hat{k} ) = 2$
• B. $\vec{r} . (\hat{i} + \hat{j} + \hat{k} ) = 6$
• C. $\vec{r} . ( 3 \hat{i} - 3 \hat{j} + 3\hat{k} ) = 2$
• D. $\vec{r} . (\hat{i} - \hat{j} + \hat{k} ) = 3$

Answer 1

Answer: (A)

$\vec{r} . (\hat{i} + \hat{j} + \hat{k} ) = 2$

Answer 2

Answer (a) $\vec{r} . (\hat{i} + \hat{j} + \hat{k} ) = 2$