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If α and β Are the Roots of 4 X 2 + 3 X + 7 = 0 , Then the Value of 1 α + 1 β is - Mathematics

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प्रश्न

If α and β are the roots of \[4 x^2 + 3x + 7 = 0\], then the value of \[\frac{1}{\alpha} + \frac{1}{\beta}\] is

पर्याय

  • \[\frac{4}{7}\]

  • \[- \frac{3}{7}\]

  • \[\frac{3}{7}\]

  • \[- \frac{3}{4}\]

MCQ

उत्तर

 −3/7

Given equation:

\[4 x^2 + 3x + 7 = 0\]

Also, 

\[\alpha\] and \[\beta\] are the roots of the equation.


Then, sum of the roots = \[\alpha + \beta = \frac{- \text { Coefficient of  }x}{\text { Coefficient of} x^2} = - \frac{3}{4}\]

Product of the roots = \[\alpha\beta = \frac{\text { Constant term }}{\text { Coefficient of } x^2} = \frac{7}{4}\]

\[\therefore \frac{1}{\alpha} + \frac{1}{\beta} = \frac{\alpha + \beta}{\alpha\beta} = \frac{- \frac{3}{4}}{\frac{7}{4}} = - \frac{3}{7}\]

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पाठ 14: Quadratic Equations - Exercise 14.4 [पृष्ठ १७]

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आरडी शर्मा Mathematics [English] Class 11
पाठ 14 Quadratic Equations
Exercise 14.4 | Q 20 | पृष्ठ १७

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