Class 9 NCERT Solutions PDF: Coordinate Geometry.
1. Two lines are drawn perpendicular to each other to locate the position of the point on a plane.
2. The horizontal line is called x-axis and the vertical line is called y-axis
3. The plane is called the cartesian or coordinate plane and the mutually perpendicular lines are called axes.
4. The x- coordinate of a point is called abscissa.
5. The y-coordinate of a point is called the ordinate.
6. The abscissa of every point is 0 on the y-axis and the ordinate is every point is 0 on the x-axis.
7. The coordinates of the origin are (0,0).
8. The axis divides the plane in four quadrants.
9. The points of the type lie in:
(+, +) – Quadrant I,
(-, +) – quadrant II
(-, -) – Quadrant III,
(+, -) – quadrant IV
10. The position of a point in a plane is determined with reference to two fixed mutually perpendicular lines, called the coordinate axes. The horizontal line called the x-axis and y-axis is called the y-axis.
11. We can represent a point in plane (called a cartesian plane or a coordinate plane) by means of an ordered pair of real numbers, called the coordinates of that point. The branch of mathematics in which geometrical problems are solved using coordinate systems in known as Coordinate Geometry.