### Functions with values in IR²

Functions with values in IR² are entered by way of the **create function **menu of the function list bar, entry **by domain+formula. **As compared with functions with values in IR, he difference is that in the formula field, two algebraic formulas are entered between brackets and separated by a comma.

Figure 132{C} Entering a function with values in IR²

The display in the algebraic tab is the same as compared with functions with values in IR. The same transformations are applicable. Each sub-function can be obtained via the sub-expression entry.

Figure 133{C} Function with values in IR ²: transformations and graphs

The graph window displays the two graphs in the same colour. The bigger pointer is for the first function. You can move it and the other follows.

### Parametric curves

After entering a function with values in IR², the corresponding parametric curve is displayed via the **create curve** menu of the Geometry tab. When moving the pointer in the graph window, a mark moves accordingly over the curve.

Figure 134{C}- Parametric curves

It is interesting to explore various configurations by changing the value of the parameter.