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If a, b `in` R, then the equation `x^(2) - abx - a^(2) = 0` hasA. one positive and one negative rootB. both positive rootsC. both negative rootsD. non-real roots |
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Answer» Correct Answer - A Let `alpha , beta` be the roots of the givn equation. Then, `alpha + beta = ab and alpha beta = - a^(2)` Also, Disc `= a^(2)b^(2) + 4a^(2) gt 0`. Thus, `alpha, beta in R` such that `alpha beta lt 0`. Therefore, one of `alpha and beta` is positive and other is negative. |
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