What is a stretch function?

A stretch function is a mathematical function that modifies the input values to produce an output that is proportionately larger or smaller, effectively stretching or compressing the graph of the function along the axes. This is often achieved by multiplying the input (or output) by a constant factor, which can alter the shape and scale of the function's graph. Stretch functions are commonly used in various fields, including physics and economics, to model changes in data or phenomena.