If a function has its input multiplied by a constant , then the graph of f is stretched by a scale factor of horizontally/parallel to the x-axis.
I hope that from the graph, it is obvious that if the y-coordinates are to be the same, the x-coordinates now needs to be halved, and thus the horizontal stretching has scale factor
![I hope that from the graph, it is obvious that if the y-coordinates are to be the same, the x-coordinates now needs to be halved, and thus the horizontal stretching has scale factor [math]\frac{1}{2}.[/math]](https://www.geogebra.org/resource/cktqghw4/j72gKgmalZ2Fz0oE/material-cktqghw4.png)