Y-axis is the vertical ruler, which helps show where an object is on a Cartesian plane; a two-dimensional mathematical graph is in the y-direction. Y here denotes vertical direction. Also, it is the starting or zero point for measuring how far to the right, or left point is on the graph. The y-axis starts at negative infinity and goes up to positive infinity. In experiments, the dependent variable is placed on the y-axis, known as an effect, and produced by the cause of the independent variable, which is placed on the x-axis. A y-axis is a line on the graph presented vertically from bottom to top. The axis is parallel to the measured coordinates, and the numbers on the y-axis are called y-coordinates. The ordered pairs are presented in parentheses, where the x-coordinate is written first and the y-coordinate after that. learn more about Learning Management System.