For some reason the desmos engine doesn't do mod(x,3)=0, perhaps it's graphing an infinately small point. If you allow the value of the modular function to be less than a small number, say, mod(x,3)<0.01, then you will see the points you expect.
Verbatim is defined as an exact repetition without changing the words. An example of verbatim is when you quote someone exactly without changing anything. word for word; in exactly the same words. Origin of verbatim.
Rule 1. Use double quotation marks to set off a direct (word-for-word) quotation. Correct: I hope you will be here, he said. Incorrect: He said that he hoped I would be there.. (The quotation marks are incorrect because hoped I would be there does not state the speaker's exact words.) Rule 2a.