Most sketches use no more than one coordinate system, but you can create additional coordinate systems if they’re needed. (For instance, you might want more than one coordinate system to compare objects — the coordinates of a point or the plot of a function — in the two systems.)
When you have more than one coordinate system, only one of those systems is the marked or active coordinate system — the one that’s used for measuring and plotting.
To change which coordinate system is marked in your sketch:
1.Identify the coordinate system you want to mark by selecting its origin, unit point, either axis, or grid. (To select a grid, click the intersection of two grid lines.)
2.Choose Graph | Mark Coordinate System.