Q98 / 200 · Manipal (MET) 2011 · Mathematics
If the roots of the equation $\frac{\alpha}{x-\alpha}+\frac{\beta}{x-\beta}=1$ be equal in magnitude but opposite in sign, then $\alpha+\beta$ is equal to
- Correct answerA0
- B1
- C2
- DNone of these
Solution
Given equation can be rewritten as
$x^2-2(\alpha+\beta) x+3 \alpha \beta=0$
Let roots be $\alpha^{\prime}$ and $-\alpha^{\prime}$.
$\therefore \quad \alpha^{\prime}+\left(-\alpha^{\prime}\right)=2(\alpha+\beta)$
$\Rightarrow \quad \alpha+\beta=0$
Hence, the correct answer is option: 'A'.