1.

5.If a and ß are the zeroes of 6x² + x-2 . Find the value of a/B+ B/a.​

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Answer

The VALUE of α/β + β/α is -25/12

\bf \large  \underline{Given : }

The QUADRATIC POLYNOMIAL

  • 6x² + X - 2
  • α and β are two zeroes of the given polynomial

\bf \large \underline{To  \: Find : }

The value of

  • α/β + β/α

\bf \large \underline{Solution : }

We have the polynomial ,

6x² + x - 2

and zeroes are α and β

Therefore , from the sum relation of zeroes

\sf sum \: of \: the \: zeroes =   - \dfrac{coefficient \: of \:  {x}}{coefficient \: of \:  {x}^{2} }  \\  \\  \implies  \sf\alpha  +  \beta  =   - \dfrac{1}{6}  \\  \\  \sf \implies  {( \alpha  +  \beta )}^{2}  =  \frac{1}{36} \\  \\ \sf  \implies  { \alpha }^{2}  +  { \beta }^{2}  + 2 \alpha  \beta  =  \frac{1}{36}  \longrightarrow(1)

And from the relation product of the zeroes and coefficients

\sf product \: of \: zeroes =  \dfrac{constant \: term}{coefficient \: of \:  {x}^{2} }

\sf\implies \alpha\beta = \dfrac{-2}{6} \\\\ \sf\implies \alpha \beta = -\dfrac{1}{3} \longrightarrow (2)

DIVIDING (2) by (1) we have ,

\sf\implies \dfrac{\alpha^{2}}{\alpha\beta}+\dfrac{\beta^{2}}{\alpha\beta}+ \dfrac{2\alpha\beta}{\alpha\beta} = \dfrac{\dfrac{1}{36}}{-\dfrac{1}{3}} \\\\ \sf\implies \dfrac{\alpha}{\beta} + \dfrac{\beta}{\alpha} + 2 = -\dfrac{1}{12} \\\\ \sf\implies \dfrac{\alpha}{\beta} + \dfrac{\beta}{\alpha} = -\dfrac{1}{12} - 2 \\\\ \sf\implies \dfrac{\alpha}{\beta} + \dfrac{\beta}{\alpha} = \dfrac{-1 - 24}{12} \\\\ \sf\implies \dfrac{\alpha}{\beta} + \dfrac{\beta}{\alpha} = -\dfrac{25}{12}

Thus , the required value of α/β + β/α is -25/12



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