While you are typing:
θ. Also see Syntax.
To graph piecewise defined functions or piecewise defined parametric curves type in each piece with the corresponding subinterval as a single function or single parametric expression.
The quickest way to type dom=(0, 2π) or dom=(-∞, ∞) is to delete the domain entirely, including dom=.
Note: Our graphing software allows you to use numerical expressions, such as π or 1+√(2), wherever you can use a literal number. This includes, for example, when specifying coordinates of a point, domain end-points, axis labels, or angles.
Remark: It's important to note that the values of trigonometric functions depend on the angle mode selected. As a result, the graphs of expressions containing trigonometric functions will (as expected) differ when changing from RAD mode (default) to other modes.