28.(2023春•包河区校级期末)函数f(x)=ex−lnxf(x)=e^{x}-lnxf(x)=ex−lnx,f′(x)f\prime (x)f′(x)是f(x)f(x)f(x)的导函数.(1)求f′(x)f\prime (x)f′(x)的单调区间;(2)证明:f(x)>2f(x)>2f(x)>2.