Correct option is C
Term 1: exlnaUsing the identity: exlna=axSo: dxd(exlna)=dxd(ax)=axlnaTerm 2: ealnxUsing the identity: ealnx=xaSo: dxd(ealnx)=dxd(xa)=axa−1Term 3: ealnaThis is constant: ealna=aaSo derivative is: dxd(aa)=0Final Answer:f′(x)=axlna+axa−1