原式=1/3∫ 1/(1-x^6)d(x^3)=1/6∫ [1/(1-x^3)+1/(1+x^3)]d(x^3)=1/6[ln(1+x^3)-ln(1-x^3)]+C
∫x^2/(1-x^6) dxletx^3 = siny3x^2 dx = cosy dy∫x^2/(1-x^6) dx=(1/3)∫secy dy=(1/3)ln|secy+tany| + C=(1/3)ln|√(1-x^6)+x^3| + C
令t等于x的立方
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