Hello Guys
Welcome to the Maths keepers In this post we will discuss about class 9th new ncert ganita manjari excercise 1.1 chapter of orienting yourself: the use of coordinates. How we can find coordinates of any point in coordinate plane.
Introduction of 2-d Cartesian Coordinate System
In the chapters on integers, rational numbers, and decimals in earlier grades, you studied the number line which is one-dimensional. The two-dimensional coordinate system uses two lines at right angles to each other to mark points in two-dimensional space. For convenience, we consider one of the lines to be horizontal; it is called the x-axis.
In coordinate plane x axis and y axis are exist and likes as horizontal line and verticle line. Another Name of x axis is abcissa and y axis another name is ordinates. Where two lines horizontal line and veritcle lines are meet together name is origin. In the verticle lines either side of 0 is postive and negative numbers.
Coordinates Axis ( x-axis and y-axis )
The other line is vertical; it is called the y-axis. The point of intersection of the x-axis and y-axis is called the origin O; its coordinates are (0, 0). Coordinate axes help us to locate any point in 2-D space using the point’s ‘coordinates’.
Distances from O are marked off in equal units, on both the axes. Distances to the right of O or upwards from O are considered positive, and distances to the left of O or downwards from O are considered negative
Point B is on the x-axis and 4.5 units to the right of O, its coordinates are (4.5, 0). This fact is written as B = (4.5, 0). Point G is on the y-axis and 4.5 units downward from O, its coordinates are (0, – 4.5), that is, G = (0, – 4.5). Point H is also on the y-axis but 4 units above O, its coordinates are (0, 4), that is, H = (0, 4). A point P = (x, 0) lies on the x-axis.
If x is positive, then P lies to the right of O. If x is negative, P lies to the left of O. A point P = (0, y) lies on the y-axis. If y is positive, P lies above O; if y is negative, P lies below O. While writing the coordinates of a point, it is often convenient to drop the ‘=’ sign and write P = (x, y) simply as P (x, y). This is especially true while marking points on a graph.
Excercise 1.1 Solutions
(i) If D1, R1 represents the door to Reiaan’s room, how far is the door from the left wall (the y-axis) of the room? How far is the door from the x-axis?
Solutions: Distance from Left wall and y axis = 8 units, Distance from right wall and x axis = 0 units
(ii) What are the coordinates of D1 ?
Solutions: Coordinates of D1 ( 8, 0 )
(iii) If R1 is the point (11.5, 0), how wide is the door? Do you think this is a comfortable width for the room door? If a person in a wheelchair wants to enter the room, will he/she be able to do so easily?
Solutions: Door width = 3.5 units and This is the comfortable room if wheelchair person enter in the room, he easily enter.
(iv) If B1 (0, 1.5) and B2 (0, 4) represent the ends of the bathroom door, is the bathroom door narrower or wider than the room door?
Solutions : Distance of bathroom door = 2.5 units and distance of room door = 3.5 unit , hence bathroom door is narrower than room door
Conclusion
This is the solution of excercise 1.1 and reianns room coordinates and you can easily solve the exercise on your behaf and solve personally. If you want to learn maths you will practice more and more. Today is completed here.
Thanks Guys
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