CLASS 9 / MATHS / COORDINATE GEOMETRY / points to remember

class -9
chapter - 3
coordinate geometry

conept-map

Points to remember –

1.     If we take two number lines, one horizontal and one vertical, and then combine them in such a way that they intersect each other at their zeroes, and then they form a Cartesian Plane.

2.     The horizontal line is known as the x-axis 

3.     the vertical line is known as the y-axis.

4.     The point where these two lines intersects each other is called the origin. It is represented as ‘O’.

5.     The Origin has zero distance from both x-axis and y-axis so that its abscissa and ordinate both are zero. So the coordinate of the origin is (0, 0)

6.     A point on the x - axis has zero distance from x-axis so coordinate of any point on the x - axis will be (x, 0)

7.     A point on the y - axis has zero distance from y-axis so coordinate of any point on the y - axis will be (0, y)

8.     The Cartesian plane is dividing into four quadrants named as Quadrant I, II, III, and IV

9.     The x-coordinate and y - coordinate of the point in the plane is written as (x, y) for point and is called the coordinates of the point

10.The x - coordinate is also called the Abscissa.

11.The y - coordinate is also called the Ordinate.

12.The positions of both the points are different in the Cartesian plane

i.e  If x ≠ y, then (x, y) ≠ (y, x), and (x, y) = (y, x), if x = y.

13.The coordinates of the points in the four quadrants will have sign according to the below table