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Statement-1: If a, b, c, A, B, C are real numbers such that `a lt b lt c`, then `f(x) = (x-a)(x-b)(x-c) -A^(2)(x-a)-B^(2)(x-b)-C^(2)(x-c)` has exactly one real root. Statement-2: If f(x) is a real polynomical and `x_(1), x_(2) in R` such that `f(x_(1)) f(x_(2)) lt 0`, then f(x) has at least one real root between `x_(1) and x_(2)`A. Statement-1 is True, Statement-2 is True, Statement-2 is a correct explanation for Statement-1.B. Statement-1 is True, Statement-2 is True, Statement-2 is not a correct explanation for Statement-1.C. Statement-1 is True, Statement-2 is False.D. Statement-1 is False, Statement-2 is True. |
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Answer» Correct Answer - D Clearly, statement-2 is true. (See Theory) We have, `f(a) = - B^(2)(a-b)-C^(2)(a-c) = - [B^(2)(a-b)+C^(2)(a-c)] gt 0 and, f(c) = - [A^(2)(c-a)+(c-b)B^(2)] lt 0` Also, `f(x) rarr - oo "as" x rarr - oo and f(x) rarr oo "as" x rarr oo`. Thus, f(x) changes its signs from positive to negative or negative to positive in the intervals `(-oo, a),(a,c) and (c, oo)`. Hence, f(x) has three real roots. |
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