Sawtooth wave as a sum of sines
Matthew Harrington 
Wikipedia gives the equation for a sawtooth waveform composed as a sum of sines as:
$$ x_\mathrm{sawtooth}(t) = \frac{A}{2}-\frac {A}{\pi}\sum_{k=1}^{\infty}\frac {\sin (2\pi kft)}{k} $$
Where $A$ is amplitude.
Is that correct? My reading of that (and graphs thereof) suggest that the initial term ($A/2-$) biases the resulting graph to positive values, so that instead of being centered around $0$ it will be centered around something $> 0$.
In comparison, they give the formula for a reverse sawtooth wave as:
$$ x_\mathrm{reversesawtooth}(t) = \frac {2}{\pi}\sum_{k=1}^{\infty} {(-1)}^{k} \frac {\sin (2\pi kft)}{k} $$
This yields values centered around 0, which is pretty much what I expected.
Simply dropping the initial term from the original expression, so that I have...
$$ x_\mathrm{sawtooth}(t) = -\frac {A}{\pi}\sum_{k=1}^{\infty}\frac {\sin (2\pi kft)}{k} $$
...yields an output range that is centered around $0$. I am writing some very simple code that deals with audio signal generation and I just want to fact check what I am doing. Is the Wikipedia page sloppy, or am I off base?
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