做个提示吧：x^2+y^2=2,x^2+y^2=2x的交点（1,1）用极坐标并考虑对称性：∫∫xdxdy=2∫(0,π/4)cosθdθ∫(√2,2cosθ)r^2dr=(2/3)∫(0,π/4)(8(cosθ)^4-2√2cosθ)dθ
