Transform
High school
A transform turns a function into another function, often to reveal hidden information or make a problem easier.
Undergraduate
A transform is an operator, usually an integral operator, that converts a function of one variable into a function of another variable.
Examples
Non-examples
Things that may be mistaken for examples.
-
$f(x) = x^2$ on $\reals$
High school
$f(x) = x^2$ on $\reals$ is not a transform, because its inputs are numbers, not elements of a space of functions.
Notes
“Transformation” also means a map from a space to itself, such as a rotation or a linear transformation. That usage is broader.