f(x)=2根号x*sinx+cosx*lnx
f'(x)=sinx /根号x+2根号x*cosx-sinx*lnx+cosx /x
f(x)=x^2-1/x^2+1
f'(x)=(2x(x^2+1)-2x(x^2-1))/(x^2+1)^2
=4x/(x^2+1)^2