# Trig identities

• Sep 30th 2009, 01:56 PM
rainer
Trig identities
Do trig identities exist for any other numbers besides 1, i, and e?
• Sep 30th 2009, 02:39 PM
Krizalid
of course, for example $\sin x=\frac{e^{ix}-e^{-ix}}{2i}.$