Cancellation at Odd Harmonics

Adding to a sinusoid at $f = 1/(2\tau)$ a version of itself delayed by $\tau$ yields cancellation at $f = 1/(2\tau)$ ,

$\scalebox{0.65}{\includegraphics{oneovertaushiftsum.eps}}$

but also at $f = 3/(2\tau)$ ,

$\scalebox{0.65}{\includegraphics{oneovertaushiftsum3.eps}}$

and at $5/(2\tau)$

$\scalebox{0.65}{\includegraphics{oneovertaushiftsum5.eps}}$

and at all odd harmonics of $f = 1/(2\tau)$ .