- AA family of circles with centre on $x-$ axis
- BA family of circles with centre on $y-$ axis
- ✓A family of rectangular hyperbola with centre on $x-$ axis
- DA family of rectangular hyperbola with centre on $y-$ axis
$\Rightarrow \frac{2 x y d y-y^{2} d x}{x^{2}}=\left(1+\frac{1}{x^{2}}\right) d x$
$\Rightarrow d\left(\frac{y^{2}}{x}\right)=d\left(x-\frac{1}{x}\right)$
$\Rightarrow \frac{y^{2}}{x}=x-\frac{1}{x}+c \Rightarrow y^{2}=x^{2}-1+c x$
$\Rightarrow\left(x+\frac{c}{2}\right)^{2}-y^{2}=1+\frac{c^{2}}{4}$
which represents a family of rectangular hyperbolas with centre on $\mathrm{x}$ -axis.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
(A rational ponit is a point both of whose coordinates are rational numbers)

$( S 1):|(\overrightarrow{ a } \times \overrightarrow{ b })+(\overrightarrow{ c } \times \overrightarrow{ b })|-|\overrightarrow{ c }|=6(2 \sqrt{2}-1)$
$( S 2): \angle ABC =\cos ^{-1}\left(\sqrt{\frac{2}{3}}\right)$. Then