Hi everyone!

I am a little bit confused how write this:

My map is: $\displaystyle F(f)(x)=\frac{1}{2}f(x)-\frac{3}{5}$. I must calculated a fixed point. I know how to do that and I now how much it is. But problem is in syntax. Is that the right one: $\displaystyle F(f(x_0))=f(x_0)$ and the result in that form $\displaystyle f(x_0)=-\frac{6}{5}$ ? Or is there $\displaystyle f_0(x)$ and not $\displaystyle f(x_0)$

Thanks in advance