I'd love your help with the following question:
Let $f(x,y)$ be a homogeneous function of degree 3. I'm trying to compute $f'_y(4,2)$, assuming that $f'_x(2,1)=1$, $f(1,0.5)=2$. by knowing that $f$ is a 3 degree homogeneous, I also know that $f(4,2)=128$, $f(2,1)=16$. I tried to use the definition of the partial derivatives, but it didn't work for me.
Thanks a lot!