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討論串[中學] 高中數學
共 91 篇文章
內容預覽:
(x-1)(x+2)>0 => x^2+x-2>0. (x^2+x-2)(x^2+ax+b) = x^4+(1-m)x^3-2x^2+3mx-2m > 0. => b = m, a = -m. => x^2-mx+m > 0 無實數解. => (-m)^2 - 4m < 0 => 0 < m < 4
(還有66個字)
內容預覽:
(x-1)(x+2)>0 => x^2+x-2>0. (x^2+x-2)(x^2+ax+b) = x^4+(1-m)x^3-2x^2+3mx-2m > 0. => b = m, a = -m. => x^2-mx+m > 0 無實數解. => (-m)^2 - 4m < 0 => 0 < m < 4
(還有4個字)