If the sum of slopes of the pair of lines given by $4 x^{2}+2 \mathrm{~h} x y-7 y^{2}=0$ is equal to the…
If the sum of slopes of the pair of lines given by $4 x^{2}+2 \mathrm{~h} x y-7 y^{2}=0$ is equal to the product of the slopes, then $\mathrm{h}$ is
$-2$
$-4$
4
$-6$
Solution
Given $4 x^{2}+2 h x y-7 y^{2}=0$
We have $\mathrm{m}_{1}+\mathrm{m}_{2}=\mathrm{m}_{1} \mathrm{~m}_{2} \Rightarrow-\frac{2 \mathrm{~h}}{7}=\frac{4}{-7} \Rightarrow \mathrm{h}=-2$