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If α ,β are roots of the equation x2 – 2x + 3 = 0 Then the equation whose roots are α3–3 α2 + 5α – 2 and β3 – β2 + β + 5 is(a) x2 + 3x + 2 = 0(b) x2– 3x – 2 = 0(c) x2 – 3x + 2 = 0(d) None |
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Answer» Correct option (c) x2 – 3x + 2 = 0 Explanation: α2 – 2α + 3 = 0 and β2 – 2β + 3 = 0 α3 – 2α2 + 3α and β3 – 2β2 + 3β P = α3 – 3α2 + 5α - 2 = 2α2 – 3α - 3α2 + 5α - 2 = α2 – 2α - 2 = 3 - 2 = 1 Similarly, we can show that Q = β3 – β2 + β + 5 = 2 Sum = 1 + 2 = 3 and product = 1 × 2 = 2 Hence x2 – 3x + 2 = 0 |
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