Question bank/JEE Main/Mathematics

JEE MainMathematicsEasyStraight Lines

If ratio of slopes of lines in kx2+4xy+3y2=0kx^{2} + 4xy + 3y^{2} = 0 is 2,
then the value of;fn lehdj.k kx2+4xy+3y2=0kx^{2} + 4xy + 3y^{2} = 0 izo.krkvksa
dk vuqikr 2

Show answer and solution
kx2+4yx+3y2=0;m1m2=2m1=2m2kx^{2} + 4yx + 3y^{2} = 0;\frac{m_{1}}{m_{2}} = 2m_{1} = 2m_{2}
m1+m2=−2hbm1m2=abm_{1} + m_{2} = \frac{- 2h}{b}m_{1}m_{2} = \frac{a}{b}
3m2=−2(2)32m22=k33m_{2} = \frac{- 2(2)}{3}2m_{2}^{2} = \frac{k}{3}
⇒k=3227≈1.185185\Rightarrow k = \frac{32}{27} \approx 1.185185

Source: Grass-G / M-25 Mathematics Paper 7 Jan.docx

More JEE Main questionsChapter practice

Need a video for this idea?

Scan any doubt from your notes and get a whiteboard explanation.

Scan a doubtView plans