Don't know the steps in finding this derivative.
But the derivative is
The answer is:
log(y)
2*y *log(y)
----------------
y
log(y) / 2 \
2*y *\1 - log(y) + 2*log (y)/
----------------------------------
2
y
log(y) / 2 3 \
2*y *\-3 - 6*log (y) + 4*log (y) + 8*log(y)/
-------------------------------------------------
3
y