11.下列选项中,函数f(x)与g(x)相同的是-|||-A. (x)=ln (x)^2, (x)=2ln x-|||-B. (x)=cos x (x)=sqrt (1-{sin )^2x}-|||-C. (x)=ln (sqrt ({x)^2+1}-x) (x)=-ln (sqrt ({x)^2+1}+x)-|||-D. (x)=1, (x)=dfrac (x)(x)