12. 求 \(\int_0^1 t^2 e^{-\alpha t} dt = ?\)
(A) \(-e^{-\alpha} \left(\frac{1}{\alpha} + \frac{2}{\alpha^2} + \frac{2}{\alpha^3}\right) + \frac{2}{\alpha^3}\)
(B) \(-e^{-\alpha} \left(\frac{1}{\alpha} + \frac{2}{\alpha^2} + \frac{2}{\alpha^3}\right)\)
(C) \(e^{-\alpha} \left(\frac{1}{\alpha} + \frac{2}{\alpha^2}\right)\)
(D) \(e^{-\alpha} \left(\frac{1}{\alpha} + \frac{1}{\alpha^2} + \frac{1}{\alpha^3}\right)\)
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統計: 尚無統計資料
統計: 尚無統計資料