(3)怎么做呢？好的加分，高等数学考研数学

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（3）码世I = ∫ dx/迟旁肢√(4x-x^2) = ∫ dx/√[4-(x-2)^2]
= ∫ d[(x-2)/2]/√{1-[(x-2)/2]^2}
= arcsin[(x-2)/2] + C
(4) I = ∫ <启雹0, +∞> dx/(x^2+4x+8) = ∫ <0, +∞> d(x+2)/[(x+2)^2+4]
= (1/2)arctan[(x+2)/2]<0, +∞> = (1/2)[π/2 - π/4] = π/8

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沉浸在热烈、

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