Z = arctan (XY), and y = e ^ x, find DZ / dy

Z = arctan (XY), and y = e ^ x, find DZ / dy

y=e^x
x=lny
z=arctan(ylny)
dz/dy
= 1/(1+y²ln²y) * (ylny)'
= ( lny+1 )/(1+y²ln²y)