Question

I don't understand why e^(-i4pi/3) is not
-cos4pi/3+isin4pi/3
but
cos4pi/3-isin4pi/3
http://i289.photobucket.com/albums/ll211/zephyrxX_Y/ScreenShot2013-04-01at73341PM_zps9ea8acfa.png

Answer 1

maybe they are the same number?

Answer 2

\(\cos(-x)=\cos(x)\) and \(\sin(-x)=-\sin(x)\) i think is what is at work here
cosine is even, sine is odd

Answer 3

ohhhh Thanks so much!! =)

Answer 4

yw