As a physicist, if you ever see units on the parameter to a trigonmetric function, you can be fairly certain something is wrong.

You can derive this from how e.g. cos(x) can be written as a polynomial series, something like 1 - x^2 + whatever; and since 1 and x^2 would have different units if x is anything but unitless, you've goofed.

That's a big reason why units are used in calculations in the first place. They basically act as a sort of checksum for your calculations.