Question

The direction ratios of two parallel lines are $4,-3,-1$ and $\lambda +\mu ,1+\mu ,2$. Then $(\lambda ,\mu )$is:

• A. $(-4,8)$
• B. $(-1,-7)$
• C. $(7,1)$
• D. $(-13,5)$

Answer 1

The correct option is A $(-4,8)$

Given DR's of two parallel line are $4,-3,-1$ and $\lambda +\mu ,1+\mu ,2$

Then Dr's should be equal

$⟹1+\mu =-3,\lambda +\mu =4$

$⟹\mu =-4,\lambda =8$