已知f（x）=x-4/x-(4a+1/a)lnx,g(x)=a-4/a-(4x-1/x)lna.f'(1)

f'(x)=1+4/x^2-(4a+1/a)/x
f'(1)=1+4-4a-1/a
g'(x)=-(4+1/x^2)lna
g'(1/2)=-(4+4)lna
由f'(1)=g'(1/2)得,
5-4a-1/a=-8lna
a=1