| Line 13: | Line 13: | ||
From first information, we can directly subtitute N into: | From first information, we can directly subtitute N into: | ||
| − | <math>x[n]=\sum_{n=0}^{3}a_ke^{jk(2\pi/2)n}</math> | + | <math>x[n]=\sum_{n=0}^{3}a_ke^{jk(2\pi/2)n}\,</math> |
| + | |||
| + | <math>x[n]=\sum_{n=0}^{3}a_ke^{jk\pi n}\,</math> | ||
Revision as of 09:54, 26 September 2008
Informations
1. $ N = 2\, $
2. $ a_k = 0\, $ for all non-fractional $ k \, $
3. $ \sum_{n=0}^{3}x[n]=2 $
4. $ \sum_{n=0}^{3}(-1)^nx[n]=5 $
Inspections
From first information, we can directly subtitute N into:
$ x[n]=\sum_{n=0}^{3}a_ke^{jk(2\pi/2)n}\, $
$ x[n]=\sum_{n=0}^{3}a_ke^{jk\pi n}\, $
