In many parts of the world, killer whales prey on fishes or marine mammals, but not both. Worldwide, killer whales have been observed preying on more than 140 species of animals, including many species of bony fish, sharks and rays, and 50 different species of marine mammals.
A coordinate system is a two-dimensional number line, for example, two perpendicular number lines or axes. This is a typical coordinate system: The horizontal axis is called the x-axis and the vertical axis is called the y-axis. The center of the coordinate system (where the lines intersect) is called the origin. The axes intersect when both x and y are zero. The coordinates of the origin are (0, 0). An ordered pair contains the coordinates of one point in the coordinate system. A point is named by its ordered pair of the form of (x, y).
In coordinate geometry and trigonometry. The coordinate plane is organized around two axes: the x-axis running horizontally, and the y-axis running vertically. The position of a point on the plane is described by two numbers that measure the distance from the point to these two reference lines. See Coordinates of a point.