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If $\alpha, \beta, \gamma$ are the roots of the equation $x^{3}-3 x^{2}+2 x-1=0$, then the value of $(1-\alpha)(1-\beta)(1-\gamma)$ is
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Verified Answer
The correct answer is:
$-1$
We have,
$x^{3}-3 x^{2}+2 x-1$
So, $\quad \alpha+\beta+\gamma=3$
$\alpha \beta+\beta \gamma+\gamma \alpha=2$
$\alpha \beta \gamma=1$
Now, $(1-\alpha)(1-\beta)(1-\gamma)$
$=1-(\alpha+\beta+\gamma)+(\alpha \beta+\beta \gamma+\gamma \alpha)-\alpha \beta \gamma$
$=1-3+2-1=-1$
$x^{3}-3 x^{2}+2 x-1$
So, $\quad \alpha+\beta+\gamma=3$
$\alpha \beta+\beta \gamma+\gamma \alpha=2$
$\alpha \beta \gamma=1$
Now, $(1-\alpha)(1-\beta)(1-\gamma)$
$=1-(\alpha+\beta+\gamma)+(\alpha \beta+\beta \gamma+\gamma \alpha)-\alpha \beta \gamma$
$=1-3+2-1=-1$
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