In a cubic equation coefficient of x^2 is zero and remaining coefficient are real has one root&

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4-2.Quadratic Equations and Inequations

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In a cubic equation coefficient of $x^2$ is zero and remaining coefficient are real has one root $\alpha = 3 + 4\, i$ and remaining roots are $\beta$ and $\gamma$ then $\alpha \beta \gamma$ is :-

A

$150$

B

$-150$

C

$25$

D

None of these

Solution

$\alpha=3+4 i$

$\beta=3-4 i$

and $\alpha+\beta+\gamma=0$

so $\gamma=-6$

$\alpha \beta \gamma=-(25)(6)=-150$

Standard 11

Mathematics

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