make pdf file generation work

quarto/precalc/transformations.qmd

@@ -111,13 +111,13 @@ $$
 If can be helpful to think of the argument to $f$ as a "box" that gets filled in by $g$:
 
 
-$$
+
 \begin{align*}
 g(x)       &=e^x - x\\
 f(\square) &= (\square)^2 + 2(\square) - 1\\
 f(g(x))    &= (g(x))^2   + 2(g(x)) - 1 = (e^x - x)^2 + 2(e^x - x) - 1.
 \end{align*}
-$$
+
 
 Here we look at a few compositions: