CBSE 2025 · Region 4 · Set 3 · Q28 · 3 marks
If $\displaystyle \alpha$ and $\displaystyle \beta$ are the zeroes of the polynomial $\displaystyle a x^{2}-x+c$. Obtain a polynomial whose zeroes are $\displaystyle \alpha-3$ and $\displaystyle \beta-3$.
Marking-scheme solution
\[\begin{aligned}
& \alpha+\beta=\frac{1}{a}, \alpha \beta=\frac{c}{a} \\
& \begin{aligned}
\text { Sum of zeroes of required polynomial } & =\alpha+\beta-6 \\
& =\frac{1}{a}-6 \text { or } \frac{1-6 a}{a}
\end{aligned} \\
& \begin{aligned}
\text { Product of zeroes of required polynomial } & =\alpha \beta-3(\alpha+\beta)+9 \\
& =\frac{c}{a}-\frac{3}{a}+9
\end{aligned}
\end{aligned}
\]
∴ required polynomial is \(\displaystyle x^{2}-\left(\frac{1-6 a}{a}\right) x+\frac{c-3+9 a}{a}\) or \(\displaystyle a x^{2}-(1-6 a) x+(c-3+9 a)\)
PolynomialsForming a Polynomial from its ZeroesApplyshort_answermedium
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CBSE Class 10 Mathematics past-paper question from the 2025board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.