Q151 / 270 · NDA 2012 (Phase 2) · Mathematics
If the roots of a quadratic equation are $m+n$ and $m-n$, then the quadratic equation will be :
- A$x^2+2 m x+m^2-m n+n^2=0$
- B$x^2+2 m x+(m-n)^2=0$
- Correct answerC$x^2-2 m x+m^2-n^2=0$
- D$x^2+2 m x+m^2-n^2=0$
Solution
$\because$ Roots are $m+n$ and $m-n$
Sum of roots $=m+n+m-n=2 m$
Product of roots $=(m+n)(m-n)=m^2-n^2$
$x^2-($ Sum of roots $) x+$ Product of roots $=0$
$x^2-2 m x+m^2-n^2=0$
Hence, the correct answer is option: 'C'.