In what direction is the graph rotated for a rotation of 90 degrees?

When discussing the rotation of a graph, particularly in the context of the Cartesian coordinate system, a rotation of 90 degrees is understood to mean a rotation around the origin (0,0). When you rotate a graph 90 degrees counterclockwise, each point on the graph moves to a new location based on the transformation of its coordinates.

For instance, if you take a point with coordinates (x, y), after a 90-degree counterclockwise rotation, the new coordinates would become (-y, x). This transformation is indicative of a counterclockwise movement. The direction of movement ensures that the orientation of the graph changes in a way that simulates a counterclockwise turn, aligning with the conventional orientation of angles in mathematics, where angles are measured from the positive x-axis in the counterclockwise direction.

In contrast, a clockwise rotation would alter the graph in the opposite direction, resulting in a different set of coordinates. The terms "linear" and "radial" do not pertain to the concept of directional rotation and hence are not applicable in this context.

Therefore, a 90-degree rotation of the graph indeed occurs in a counterclockwise direction, confirming the choice selected.