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If `alpha, beta, gamma` are the roots of `x^(3) + ax^(2) + b = 0`, then the value of `|(alpha,beta,gamma),(beta,gamma,alpha),(gamma,alpha,beta)|`, isA. `-a^(3)`B. `a^(3) -3b`C. `a^(3)`D. `a^(2) - 3b` |
Answer» Correct Answer - C Since, `alpha, beta , gamma` are the roots of the given equations `:. alpha + beta + gamma = -a, alpha beta + beta gamma + gamma alpha = 0 and alpha beta gamma = -b` `Delta = |(alpha,beta,gamma),(beta,gamma,alpha),(gamma,alpha,beta)|` `Delta = - (alpha + beta + gamma) (alpha^(2) + beta^(2) + gamma^(2) - alpha beta - beta gamma - gamma alpha)` `Delta = - (alpha + beta + gamma) {(alpha + beta + gamma)^(2) - 3(alpha beta + beta gamma + gamma beta)}` `Delta = - (-a) {(a^(2) - 0)} = a^(3)` |
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