Graphing $f(2-x)$
Denote $g(x)=f(2-x)$ and set $x'=2-x$. What you want is drawing the graph of $g$. Now the points $x$ and $x'$ are symmetric (on the $x$-axis) w.r.t. the point $1$ since $\frac{x+x'}2=1$, and $g(x)=f(x')$. Therefore the graph of $g$ is the symmetric of the graph of $f\,$ w.r.t. the line $x=1$.