HP 15c Collector's Edition Owner's Handbook Manual page 134

122 Section 11: Calculating With Complex Numbers
Example:
Keystrokes
´ •
4
2 v
3
´ V
4 v
5
´ V
+
´ %
i i
Display
2.0000
3
2.0000
4.0000
5
4.0000
6.0000
8.0000
6.0000
´ V
%