- #1
TSN79
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I'm currently working with Fourier-series and have to integrate some expressions, like this one:
[tex]2\int_{0}^{1} (1-x)*sin(n \omega x) dx = 2 \left[- \frac{1}{n \pi}(1-x) cos(n \pi x) - \frac{1}{(n \pi)^2} sin(n \pi x) \right]_{0}^{1} = \frac{2}{n \pi}[/tex]
Trying to evaluate this (with [tex]\omega = \pi[/tex])on the TI-89 does not give this result. And the thing is that if I remove the n from the sine and cosine expressions, then the answer comes out right. Why is this? Should I assume the n is 1 in the sine and cosine functions in the square parentheses?
[tex]2\int_{0}^{1} (1-x)*sin(n \omega x) dx = 2 \left[- \frac{1}{n \pi}(1-x) cos(n \pi x) - \frac{1}{(n \pi)^2} sin(n \pi x) \right]_{0}^{1} = \frac{2}{n \pi}[/tex]
Trying to evaluate this (with [tex]\omega = \pi[/tex])on the TI-89 does not give this result. And the thing is that if I remove the n from the sine and cosine expressions, then the answer comes out right. Why is this? Should I assume the n is 1 in the sine and cosine functions in the square parentheses?