第1个回答 2020-06-05
1、(1)面积=∫(1,3) (x-1/x)dx
=(x^2/2-ln|x|)|(1,3)
=9/2-ln3-1/2
=4-ln3
(2)面积=∫(-√2,√2) (4-y^2-y^2)dy
=4∫(0,√2) (2-y^2)dy
=4*(2y-y^3/3)|(0,√2)
=4*(2√2-2√2/3)
=16√2/3
2、体积=∫(-2,0) π*(2x+4)^2dx
=4π∫(-2,0) (x^2+4x+4)dx
=4π*(x^3/3+2x^2+4x)|(-2,0)
=4π*(8/3-8+8)
=32π/3本回答被网友采纳