z=arctan(xy),而y=e^x,求dz/dy

z=arctan(xy),而y=e^x,求dz/dy

y=e^x
x=lny
z=arctan(ylny)
dz/dy
= 1/(1+y²;ln²;y)*(ylny)'
=(lny+1)/(1+y²;ln²;y)