fog/gof

diff --git a/methods/transformations.md b/methods/transformations.md
index 121c02cb8885c8348488f116551be12c9918c263..c9e5cd115d20963f03760f4d109482acf30e5be6 100644 (file)
--- a/methods/transformations.md
+++ b/methods/transformations.md
@@ -112,4 +112,8 @@ Product functions:
 
 Find new point $(x^\prime, y^\prime)$. Substitute these into original equation to find image with original variables $(x, y)$.
 
+## Composite functions
+
+$(f \circ g)(x)$ is defined iff $\operatorname{ran}(g) \subseteq \operatorname{dom}(f)$
+