解: ∫x/(4x²+4x+5) dx=∫x/[(2x+1)²+1] dx=∫[(x+1/2)-1/2]/[(2x+1)²+1] dx=∫(x+1/2)/[(2x+1)²+1] dx-∫(1/2)/[(2x+1)²+1] dx=1/8 ∫1/[(2x+1)²+1] d(2x+1)²-1/4 ∫1/[(2x+1)²+1] d(2x+1)=1/8 ln(2x+1)²-1/4 arctan(2x+1)+C
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