If $\alpha, \beta$ are the zeros of the polynomial $f(x)=a x^{2}+b x+c$, then $\frac{1}{\alpha^{2}}+\frac{1}{\beta^{2}}=$
(a) $\frac{b^{2}-2 a c}{a^{2}}$
(b) $\frac{b^{2}-2 a c}{c^{2}}$
(c) $\frac{b^{2}+2 a c}{a^{2}}$
(d) $\frac{b^{2}+2 a c}{c^{2}}$
We have to find the value of $\frac{1}{\alpha^{2}}+\frac{1}{\beta^{2}}$
Given $\alpha$ and $\beta$ are the zeros of the quadratic polynomial $\mathrm{f}(\mathrm{x})=a x^{2}+b x+c$
$\alpha+\beta=\frac{-\text { Coefficient of } x}{\text { Coefficient of } x^{3}}$
$=\frac{-b}{a}$
$\alpha \beta=\frac{\text { Constant term }}{\text { Coefficient of } x^{2}}$
$=\frac{c}{a}$
We have,
$\frac{1}{\alpha^{2}}+\frac{1}{\beta^{2}}=\left(\frac{1}{\alpha}+\frac{1}{\beta}\right)^{2}-\frac{2}{\alpha \beta}$
$\frac{1}{\alpha^{2}}+\frac{1}{\beta^{2}}=\left(\frac{\beta}{\alpha \beta}+\frac{\alpha}{\beta \alpha}\right)^{2}-\frac{2}{\alpha \beta}$
$\frac{1}{\alpha^{2}}+\frac{1}{\beta^{2}}=\left(\frac{\alpha+\beta}{\alpha \beta}\right)^{2}-\frac{2}{\alpha \beta}$
$\frac{1}{\alpha^{2}}+\frac{1}{\beta^{2}}=\left(\frac{\frac{-b}{a}}{\frac{c}{a}}\right)^{2}-\frac{2}{\frac{c}{a}}$
$\frac{1}{\alpha^{2}}+\frac{1}{\beta^{2}}=\left(\frac{-b}{a} \times \frac{a}{c}\right)^{2}-\frac{2}{c}$
$\frac{1}{\alpha^{2}}+\frac{1}{\beta^{2}}=\left(\frac{-b}{c}\right)^{2}-\frac{2 a}{c}$
$\frac{1}{\alpha^{2}}+\frac{1}{\beta^{2}}=\left(\frac{b^{2}}{c^{2}}\right)-\frac{2 a \times c}{c \times c}$
$\frac{1}{\alpha^{2}}+\frac{1}{\beta^{2}}=\left(\frac{b^{2}}{c^{2}}\right)-\frac{2 a c}{c^{2}}$
$\frac{1}{\alpha^{2}}+\frac{1}{\beta^{2}}=\left(\frac{b^{2}-2 a c}{c^{2}}\right)$
Hence, the correct choice is $(b)$
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