Q174 / 270 · NDA 2012 (Phase 1) · Mathematics
The equation formed by multiplying each root of $a x^2+b x$ $+c=0$ by 2 is $x^2+36 x+24=0$.
Which one of the following is correct?
- A$b c=a^2$
- B$b c=36 a^2$
- C$b c=72 a^2$
- Correct answerD$b c=108 a^2$
Solution
$\begin{aligned}
& b=18 a \\
& c=6 a
\end{aligned}$
For the next Three (3) questions that follow: Let $\sin (\mathrm{A}+\mathrm{B})=1$ and $\sin (\mathrm{A}-\mathrm{B})=\frac{1}{2}$, where $\mathrm{A}, \mathrm{B} \in\left[0, \frac{\pi}{2}\right]$.
Hence, the correct answer is option: 'D'.