Chapter 22 – Introduction to Coordinate Geometry – RS Aggarwal Solutions for class 8
Coordinate geometry is an interesting topic for the students.
Coordinate geometry is also known as analytic geometry. With the help of this concept, position of a point can be determined using the coordinates. It is geometry in two dimensions.
The above figure is a Cartesian plane in which there are two lines XOX’ and YOY’ perpendicular to each other. These lines are known as coordinate axis
Origin: The point at which both the axes intersect each other
XOX’: It is the X axis of Cartesian plane. It is the horizontal axis.
YOY’: It is the Y axis of Cartesian plane. It is the vertical axis.
There are four quadrants in the Cartesian plane which are as follows:
Quadrant 1: XOY with sign (+, +)
Quadrant 2: YOX’ with sign (-, +)
Quadrant 3: X’OY’ with sign (-, -)
Quadrant 4: Y’OX with sign (+, -)
Order pair: Any of the point in the Cartesian plane can be represented in the form of (a, b) which is known as ordered pair, where a is the x-coordinate known as abscissa of the point and b is the y-coordinate known as ordinate of the point
Note: Every point on the x-axis is of the form (x, 0) which means that on the x axis, y-coordinate is zero. Likewise, every point on y-axis is of the form (0, y) which means that on the y axis, x-coordinate is zero.