Angel Dust on 10/10/2007 at 03:24
I need help in simplifying the following expression:
sin(n pi / 2)
You get answers like 0,1,0,-1 ... for n = 0,1,2,3.. but I need to the simple version of it like how
cos(n pi) = (-1)^(n+2)
Ofcourse there might not be a nice simple little expression for it but any help would be appreciated.
Ghostly Apparition on 10/10/2007 at 04:05
How to use forums to do your math homework for you. :eek:
crunchy on 10/10/2007 at 04:26
I'm a math tutor so I can help. My rate is $40/hour.
Scots Taffer on 10/10/2007 at 04:31
my god ask me algebraic theory anything but calculus and trigonometrical expression god that can just fuck off and die
Mortal Monkey on 10/10/2007 at 06:22
cos z = <sup>1</sup>/<sub>2</sub> (e<sup>iz</sup> + e<sup>-iz</sup>)
Angel Dust on 10/10/2007 at 08:32
Its not for an assignment I'm just working though last years exam in preparation. Its also only a tiny part of the problem (a Fourier cosine series problem, its one of those things you should know of by heart but I can't remember it. I've tried looking around but though I might try here since there seemed to be some smart people here. I guess I'll just ask my lecturer tommorrow.
Chade on 10/10/2007 at 10:17
I think I must be missing something ... ???
The example you gave only works for integers, no? Unless there is a way of converting the complex part of the number into the correct fraction which gives the correct result, which might well be the case. Maybe I just haven't seen it before. I'm no expert on complex numbers, that's for sure!
However, assuming you only need the equation to work for integers, then why not just take the real part of -1^(n/2 - 0.5)?
dvrabel on 10/10/2007 at 11:58
That sort of stuff was always in the databook when I covered Fourier series and transforms at uni.
