👉 Invariance, also known as invariance under change of variables, is a concept in mathematics that refers to an object or system being unchanged by a specific set of transformations. In other words, it means that the properties and behavior of the object remain constant regardless of the transformation applied. For example, if we have two functions f(x) and g(x), where x represents a variable, then invariance under change of variables states that their composition f(g(x)) remains equal to f
