If α and β are the roots of the equation x² + px + 2 = 0 and 1/α and 1/β are the roots of the equation 2x² + 2qx + 1 = 0, then (α - 1/β)(β - 1/α)(α + 1/β)(β + 1/α) is equal to:
If α and β are the roots of the equation x² + px + 2 = 0 and 1/α and 1/β are the roots of the equation 2x² + 2qx + 1 = 0, then (α - 1/β)(β - 1/α)(α + 1/β)(β + 1/α) is equal to:
Option 1 -
9/4(9 – p²)
Option 2 -
9/4(9 + q²)
Option 3 -
9/4(9 - q²)
Option 4 -
9/4(9 + p²)
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1 Answer
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Correct Option - 4
Detailed Solution:α, β are roots of x² + px + 2 = 0
⇒ α² + pα + 2 = 0 and β² + pβ + 2 = 0
⇒ 1/α, 1/β are roots of 2x² + px + 1 = 0
But 1/α, 1/β are roots of 2x² + 2qx + 1 = 0
⇒ p = 2q
Also α + β = -p, αβ = 2
(α - 1/α) (β - 1/β) (α + 1/β) (β + 1/α)
= ( (α²-1)/α ) ( (β²-1)/β ) ( (αβ+1)/β ) ( (αβ+1)/α )
= ( (-pα-3) (-pβ-3) (αβ+1)² ) / ( (αβ)² )
= 9/4 (p²αβ + 3p (α + β) +...more
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