积分
∫(0,1)dx∫(0,1-x)dy∫(0,6-x²-y²)dz
=∫(0,1)dx∫(0,1-x)(6-x²-y²)dy
=∫(0,1)(6y-x²y-y³/3)|(0,1-x)dx
=∫(0,1)[(6(1-x)-x²(1-x)-(1-x)³/3)dx
=∫(0,1)[(6-6x-x²+x³-(1-3x+3x²-x³)/3)dx
=∫(0,1)[(6-6x-x²+x³-1/3+x-x²+x³/3)dx
=∫(0,1)[(17/3-5x-2x²+4x³/3)dx
=(17x/3-5x²-2x³/3+x^4/3)|(0,1)
=17/3-5-2/3+1/3
=(34-30-4+2)/6
=1/3
用二重积分,理解了他的几何意义会简单很多!
。。。。。。比v给出个,个,恭喜恭喜小嘎血压擦擦