Let's consider a code example showing what would be allowed (or not) using different levels of inheritance: 1  class BaseClass {}; void freeStandingFunction(BaseClass* b); class DerivedProtected : protected BaseClass { DerivedProtected() { freeStandingFunction(this); // Allowed } };
Definition of Horizontal Axis. Horizontal means flat or level. Horizontal axis is the x-axis on a graph. The blue number line in the figure below is the x-axis, the horizontal axis.
The x axis is a horizontal line and the y axis, which is perpendicular to the x axis, is a vertical line. The rectangular coordinate system that can be sued for determination of the concrete position of some geometric figure in the three-dimensional space requires selecting three mutually perpendicular lines: x axis, y axis and z axis.