Lesson 2 of 10 · 6 min
Coordinate axes and coordinate planes
NCERT §11.2
To log every flight the same way, the club fixes three directions at the pad: x towards the gate, y towards the pavilion, z straight up. What exactly are the axes and planes they have set up?
The lesson in notes
In short
Take three planes that meet at one point O and are each perpendicular to the other two. They cut one another along three lines X′OX, Y′OY and Z′OZ, the x, y and z-axes, which are also mutually perpendicular. Together they form the rectangular coordinate system.
The plane holding the x and y-axes is the XY-plane; similarly there are the YZ-plane and the ZX-plane. These three are the coordinate planes, and O, where all three axes meet, is the origin.
Picture the XY-plane as horizontal, like the page lying on a desk. The z-axis then stands vertical.
Sign rules: distances above the XY-plane (along OZ) are positive and those below it (along OZ′) negative; distances to the right of the ZX-plane (along OY) are positive, to its left negative; distances in front of the YZ-plane (along OX) are positive, behind it negative.