TOPICS

Unit-3(Examples)

Coordinate Geometry

**Example-1 :-** See Fig. and complete the following statements:

(i) The abscissa and the ordinate of the point B are _ _ _ and _ _ _, respectively.

Hence, the coordinates of B are (_ _, _ _).

(ii) The x-coordinate and the y-coordinate of the point M are _ _ _ and _ _ _,

respectively. Hence, the coordinates of M are (_ _, _ _).

(iii) The x-coordinate and the y-coordinate of the point L are _ _ _ and _ _ _,

respectively. Hence, the coordinates of L are (_ _, _ _).

(iv) The x-coordinate and the y-coordinate of the point S are _ _ _ and _ _ _,

respectively. Hence, the coordinates of S are (_ _, _ _).

(i) Since the distance of the point B from the y - axis is 4 units, the x - coordinate or abscissa of the point B is 4. The distance of the point B from the x - axis is 3 units; therefore, the y - coordinate, i.e., the ordinate, of the point B is 3. Hence, the coordinates of the point B are (4, 3). As in (i) above : (ii) The x - coordinate and the y - coordinate of the point M are –3 and 4, respectively. Hence, the coordinates of the point M are (–3, 4). (iii) The x - coordinate and the y - coordinate of the point L are –5 and – 4, respectively. Hence, the coordinates of the point L are (–5, – 4). (iv) The x - coordinate and the y- coordinate of the point S are 3 and – 4, respectively. Hence, the coordinates of the point S are (3, – 4).

**Example-2 :-** Write the coordinates of the points marked on the axes in Fig.

(i) The point A is at a distance of + 4 units from the y - axis and at a distance zero from the x - axis. Therefore, the x - coordinate of A is 4 and the y - coordinate is 0. Hence, the coordinates of A are (4, 0). (ii) The coordinates of B are (0, 3). (iii) The coordinates of C are (– 5, 0). (iv) The coordinates of D are (0, – 4). (v) The coordinates of E are (2/3, 0).

**Example-3 :-** Locate the points (5, 0), (0, 5), (2, 5), (5, 2), (–3, 5), (–3, –5), (5, –3) and (6, 1) in the Cartesian plane.

Taking 1cm = 1unit, we draw the x - axis and the y - axis.

**Example-4 :-** Plot the following ordered pairs (x, y) of numbers as points in the Cartesian plane. Use the scale 1cm = 1 unit on the axes.

Taking 1cm = 1unit, we draw the x - axis and the y - axis. The pairs of numbers given in the table can be represented by the points (– 3, 7), (0, –3.5), (– 1, – 3), (4, 4) and (2, – 3).

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