Trigonometry system - complex conjugate I have the following function
$$e_n(t) = e^{2\pi int}, t \in R, n \in Z$$
Could anyone explain how one can go from this:
$$e_m(t) \bar e_n(t) $$
to
$$e^{-2\pi i(m - n)t}$$

Shouldn't it be $e^{2\pi i(m - n)t}$ instead of $e^{-2\pi i(m - n)t}$?
If $e_n(t)=e^{2πint}$, the conjugate is $\bar{e}_n(t)=e^{-2πint}$

Then

$e_m(t)\bar{e}_n(t)=e^{2πimt}e^{-2πint}=e^{-2πi(n-m)t}.$
If $e_n(t)=e^{2πint}$, the conjugate is $\bar{e}_n(t)=e^{-2πint}$

Then

$e_m(t)\bar{e}_n(t)=e^{2πimt}e^{-2πint}=e^{-2πi(n-m)t}.$