# I Periodic potential V(x) -- how can I show that the period is d?

#### GAB1

periodic potential

how can i show that period is d

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#### RPinPA

If $f(x)$ has a period of $d$ then $f(x) = f(x + d)$ for all $x$.

Change $x$ to $x + d$. See what happens.

I should note that this only establishes the $d$ is a period. If you shift a sine wave of period $T$ by 10 periods, you get the same sine wave, so $10T$ is a period but not the smallest period. You have to do a little more reasoning to establish that $d$ is the smallest period.

#### Mark44

Mentor
Thread closed as the OP has been banned.

"Periodic potential V(x) -- how can I show that the period is d?"

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