Final answer:
Movement to the left in the coordinate plane is controlled by the x-coordinate and is considered to be in the negative x direction according to mathematical conventions.
Step-by-step explanation:
When we move left in the coordinate plane, which consists of the x and y coordinates, the movement is controlled by the x-coordinate. In a standard coordinate system, moving to the left signifies moving in the negative x direction. This is because, by convention in mathematics, movement to the right is considered to be in the positive direction along the x-axis, and movement to the left is in the negative direction. It is important to note that this convention of directionality is consistent with vector quantities, where unit vectors î (for the x-axis) and ç (for the y-axis) define the positive directions in the coordinate plane.