system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is the vertical axis represented with a Y and the horizontal axis with an X and not other letters or symbols? Does it have any history or reason to be?
gpt
From wikipedia: The axes may then be referred to as the X-axis and Y-axis. The choices of letters come from the original convention, which is to use the latter part of the alphabet to indicate unknown values. The first part of the alphabet was used to designate known values.