已知函数 z=z(x,y)z=z(x,y) 由 z+lnz−∫yxxe−t2dt=1z+\ln z-\int_{y}^{x}xe^{-t^2}dt=1 确定,则 ∂2z∂x2∣(1,1)=\left.\frac{\partial^2z}{\partial x^2}\right|_{(1,1)}=______
18e2\frac{1}{8e^2}
2