If $\alpha$ and $\beta$ are the zeroes of the polynomial $x^2 - 1$, then the value of $(\alpha + \beta)$ is

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## Model Answer **Option D: 0** For $x^2 - 1$, we have $a = 1,\ b = 0,\ c = -1$. So $\alpha + \beta = \dfrac{-b}{a} = \dfrac{0}{1} = 0$. ## Explanation Use the formula $\alpha + \beta = \frac{-b}{a}$. Since the polynomial $x^2 - 1$ has no $x$ term, $b = 0$, making the sum of zeroes zero. (Alternatively, zeroes are $+1$ and $-1$, which add to 0.)

Mathematics — CBSE Class 10 board question