Question

# The direction ratios of the line $$x-y+z-5=0=x-3y-6$$ are

A
3,1,2
B
2,4,1
C
314,114,214
D
241,441,141

Solution

## The correct option is A $$3,1,-2$$Normals of $${ P }_{ 1 },{ P }_{ 2 }$$ gives the direction ratios of line of intersection, i.e. cross-product$$(\hat { i } -\hat { j } +\hat { k } )\times (\hat { i } -3\hat { j } -0\hat { k } )$$ $$\begin{vmatrix} i & j & k \\ 1 & -1 & 1 \\ 1 & -3 & 0 \end{vmatrix}=3\hat { i } -(-1)\hat { j } +(-2)\hat { k }$$$$=3\hat { i } +\hat { j } -2\hat { k }$$Maths

Suggest Corrections

0

Similar questions
View More

People also searched for
View More