For a sine wave $x=A\sin(ωt+\varphi)$,

  • $A$ is the amplitude
  • $\omega$ is the frequency
  • $\varphi$ is the phase

What is $(ωt+\varphi)$ called? "Angle"? I can't find any source call that part.


2 Answers 2


$\omega t + \varphi$ is called the phase. See this Wikipedia article for the details.

The symbol $\varphi$ is known variously as the phase shift, phase offset or phase constant.

  • 1
    $\begingroup$ Wikipedia is not an authority on the use is scientific or technical terminology. In common speech, $\varphi$ is called both the "phase" and the "phase offset", and probably other things, all determined by context. It is misleading to claim that there's a universal and consistent use of terms. $\endgroup$
    – DanielSank
    Commented Mar 25, 2018 at 17:00

As with functions in general, the quantity inside $\sin$ here is called an argument.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.