Q108 / 160 · TS EAMCET 2022 (20 Jul Shift 2) · Mathematics
If $y=\frac{a x+b}{c x+d}$, than $\frac{d x}{d y}=$
- A$\frac{a d-b c}{(a x+b)^2}$
- Correct answerB$\frac{a d-b c}{(a-c y)^2}$
- C$\frac{a d+b c}{(c x+d)^2}$
- D$\frac{a d+b c}{(a+c y)^2}$
Solution
Given $y=\frac{a x+b}{c x+d}$
$\Rightarrow \mathrm{x}=\frac{\mathrm{b}-\mathrm{yd}}{\mathrm{yc}-\mathrm{a}}$
$\text { now } \frac{\mathrm{dx}}{\mathrm{dy}}=\frac{\mathrm{ad}-\mathrm{bc}}{(\mathrm{yc}-\mathrm{a})^2}$
Hence, the correct answer is option: 'B'.