Frequently, functions are defined by several equations rather than by a single one. For ex...

Frequently, functions are defined by several equations rather than by a single one. For example, we may define |x| by

This would be described on a TI by Y1 = (−X)(X<0)+X(X≥0); on a Casio it would be Y1 = −X,[−9.4,0] Y2 = X,[0,9.4]. Graph