y*log(y)
Apply the product rule:
f(y)=yf{\left(y \right)} = yf(y)=y; to find ddyf(y)\frac{d}{d y} f{\left(y \right)}dydf(y):
Apply the power rule: yyy goes to 111
g(y)=log(y)g{\left(y \right)} = \log{\left(y \right)}g(y)=log(y); to find ddyg(y)\frac{d}{d y} g{\left(y \right)}dydg(y):
The derivative of log(y)\log{\left(y \right)}log(y) is 1y\frac{1}{y}y1.
The result is: log(y)+1\log{\left(y \right)} + 1log(y)+1
The answer is:
1 + log(y)
1 - y
-1 --- 2 y