7.f'(x)=e^xk=f'(0)=1切线y-1=xy=x+1 k1=-1/k=-1法线y-1=-xy=-x+18. y' =3^xln3k = y'(0) = ln3切线：y-3=ln3(x-1)法线：y-3 = -1/ln3(x-1)
