（1）将x=y²代入积分得：∫[1--->2] [(y²+y)*2y+(y-y²)] dy=∫[1--->2] (2y³+y²+y) dy=(1/2)y⁴+(1/3)y³+(1/2)y² |[1---->2]=8+8/3+2-1/2-1/3-1/2=34/3（2）点（1,1）到（4...
（1）将x=y²代入积分得：∫[1--->2] [(y²+y)*2y+(y-y²)] dy=∫[1--->2] (2y³+y²+y) dy=(1/2)y⁴+(1/3)y³+(1/2)y² |[1---->2]=8+8/3+2-1/2-1/3-1/2=34/3（2）点（1,1）到（4...