If the distance between the parallel lines given by the equation $x^2+4 x y+4 y^2+3 x+6y-4=0$ is $\lambda$,…
If the distance between the parallel lines given by the equation $x^2+4 x y+4 y^2+3 x+6y-4=0$ is $\lambda$, then $\lambda^2=$
- $5$
- $\sqrt{5}$
- $25$
- $\frac {9}{5}$
Solution
Given equation is
$\begin{aligned}
& x^2+4 x y+4 y^2+3 x+6 y-4=0 \\
& (x+2 y)^2+3(x+2 y)-4=0 \\
& (x+2 y+4)(x+2 y-1)=0
\end{aligned}$
$\therefore \quad$ The lines are: $x+2 y+4=0$ and $x+2 y-1=0$
$\begin{aligned}
\therefore \quad \text { Required distance } & =\frac{|4-(-1)|}{\sqrt{1+4}} \\
& =\frac{5}{\sqrt{5}}=\sqrt{5} \text { units }
\end{aligned}
$
$\lambda=\sqrt{5}$ units
$\lambda^2=5$
Asked in: MHT CET 2023 (09 May Shift 1)
Practice more Straight Lines questions on Aicharya