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If $\alpha$ and $\beta$ are the zeroes of $2 \mathrm{x}^{2}+5 \mathrm{x}-9$, then the value of $\alpha \beta$ is (a) $\frac{-5}{2}$ (b) $\frac{5}{2}$ (c) $\frac{-9}{2}$ (d) $\frac{9}{2}$
If $\alpha$ and $\beta$ are the zeroes of $2 \mathrm{x}^{2}+5 \mathrm{x}-9$, then the value of $\alpha \beta$ is (a) $\frac{-5}{2}$ (b) $\frac{5}{2}$ (c) $\frac{-9}{2}$ (d) $\frac{9}{2}$
CBSE | Class 10 | Excercise 2D | Maths | Polynomials | RS Aggarwal
If $\alpha$ and $\beta$ are the zeroes of $2 \mathrm{x}^{2}+5 \mathrm{x}-9$, then the value of $\alpha \beta$ is (a) $\frac{-5}{2}$ (b) $\frac{5}{2}$ (c) $\frac{-9}{2}$ (d) $\frac{9}{2}$

The correct option is option (c) $\frac{-9}{2}$

$\alpha$ and $\beta$ be the zeroes of $2 \mathrm{x}^{2}+5 \mathrm{x}-9$.

If $\alpha+\beta$ are the zeroes, then $\mathrm{x}^{2}-(\alpha+\beta) \mathrm{x}+\alpha \beta$ is the required polynomial.

The polynomial will be $\mathrm{x}^{2}-\frac{5}{2} \mathrm{x}-\frac{9}{2}$

$\therefore \alpha \beta=\frac{-9}{2}$

i

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