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Let α, β be the roots of the equation (x – a) (x – b) = c, c ≠ 0, then the roots of the equation (x – α) (x – β) + c = 0 are :(a) a, c (b) b, c (c) a, b (d) a + c, b + c |
Answer» (c) a, b The given equation is (x – a) (x – b) = c ⇒ x2 – (a + b)x + (ab – c) = 0 As α, β are the roots of this equation, so α + β = a + b and αβ = ab – c Let γ , δ be the roots of the equation (x – α) (x – β) + c = 0 i.e., γ , δ are the roots of the equation x2 – (α + β)x + (αβ + c)= 0 ∴ γ + δ = α + β = a + b ...(i) γδ = αβ + c = – c + c = ab ...(ii) ∴ From (i) and (ii) we can infer that the roots of the equation (x – α) (x – β) + c = 0 are a and b. |
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