Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa

If for some \alpha \in R, the lines L_1 : \frac{x+1}{2} = \frac{y-2}{-1} = \frac{z - 1}{1} and L_2 : \frac{x+2}{\alpha} = \frac{y+1}{5-\alpha} = \frac{z + 1}{1} are coplanar then the line L2 passes through the point:  
Option: 1 (2,-10, -2)   
Option: 2  (10,2,2)   
Option: 3 10,-2,-2)     
Option: 4  (-2,10,2)

Answers (1)

best_answer

Given equations of line 

L_1 : \frac{x+1}{2} = \frac{y-2}{-1} = \frac{z - 1}{1}

L_2 : \frac{x+2}{\alpha} = \frac{y+1}{5-\alpha} = \frac{z + 1}{1}

For the coplanarity of two lines

\\\begin{vmatrix} -1+2 &2+1 &1+1 \\ 2 &-1 &1 \\ \alpha& 5-\alpha & 1 \end{vmatrix}=0\\1(-1-5+\alpha)-3(2-\alpha)+2(10-2\alpha+\alpha)=0\\\alpha=-4

Now

\\\L_2:\frac{x+2}{-4}=\frac{y+1}{9}=\frac{z+1}{1}\\\text{point }(2,-10,-2)\;\text{satisfy the equation.}

Posted by

himanshu.meshram

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE

Similar Questions

Trending Articles/News

anam-khan

JEE Main 2024 Topper: Farmer’s son Gajare Nilkrishna says ‘keep questioning until you understand’
anam-khan

NIT Puducherry Cut-off 2024: Computer Science and Engineering had highest closing rank last year
anam-khan

What after JEE Main results 2024? All you need to know about JEE Adv, CSAB, JoSAA counselling

Latest Question