1. HOW TO FIND A POINT ON A SURFACE CARTESIAN PLANE

2. To find a point on a surface, many different systems are available. Most frequently used are: 1.ALPHANUMERIC system (mostly in Geography and road maps) 2. Cartesian Plane (especially in Mathematics)

3. The Cartesian Plane is made of: 1.Two axes: one horizontal (called the x-axis) one vertical (called the y-axis) 2. A graduation (it has to be very clear) on every axis x y O The origin O Y-axis X-axis 1 1

4. The graduation can be confusing, that’s why it has to be VERY CLEAR Point A: its x-coordinate is 3 and and its y-coordinate is -1 So its COORDINATES are (3,-1). Careful x is first, then y. x y O.A.A 1 1.B.B Point B: its x is -1 and its y is 2 So its COORDINATES are (-1,2)

5. x y O.A.A 12 7.B.B Now point A has an x-coordinate of 36 and y-coordinate of -7 So its COORDINATES are (36,-7) Point B has an x-coordinate of -12 and a y-coordinate of 14 So its COORDINATES are (-12,14) When changing the graduations on the x and y axis, the coordinates of the points will be different.

6. x y O.A.A 12 7.B.B Point A has an x-coordinate of 18 and y-coordinate of 7 So its COORDINATES are (18,7) Point B has an x-coordinate of 12 and a y-coordinate of 11 So its COORDINATES are (12,11) Cuts are permitted on one or both axes, but the next graduation becomes compulsory. 15 9

7. x y O.A.A 1 1.B.B.C.C.E.E.D.D On the Cartesian Plane there are 4 quadrants. Quadrant 1 Quadrant 2 Quadrant 4 Quadrant 3 In quad 1, the points have (+,+) In quad 2, the points have (-,+) In quad 3, the points have (-,-) In quad 4, the points have (+,-)

8. If a point is directly on the x-axis, its y-coordinate is 0. If a point is directly on the y-axis, its x-coordinate is 0. VERY IMPORTANT: The coordinates of a point CAN BE DECIMALS