Q202 / 270 · NDA 2023 (Phase 1) · Mathematics
[QUESTION]
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Question:
If $\Delta(7,4,2, \alpha)=0$, then $\alpha$ is a root of which one of the following equation?
Question: If $\Delta(7,4,2, \alpha)=0$, then $\alpha$ is a root of which one of the following equation?
- A$7 x^2+4 x+2=0$
- B$7 x^2-4 x+2=0$
- Correct answerC$7 x^2+8 x+2=0$
- D$7 x^2-8 x+2=0$
Solution
$\Delta(7,4,2, \alpha)=0$
$a=7, b=4, c=2$
$a \alpha^2+2 b \alpha+c=0$
$7 \alpha^2+8 \alpha+2=0$
$\therefore \quad \alpha$ is a root of $7 x^2+8 x+2=0$
Hence, the correct answer is option: 'C'.