∫[0→√2] x√(2-x²) dx=(1/2)∫[0→√2] √(2-x²) d(x²)=-(1/2)∫[0→√2] √(2-x²) d(2-x²)=-(1/2)(2/3)(2-x²)^(3/2) |[0→√2]=(1/3)·2^(3/2)=2√2/3若有不懂请追问,如果解决问...