# What is the name of $(ωt+\varphi)$ in sine wave?

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.

$\omega t + \varphi$ 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.
• 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. Mar 25 '18 at 17:00
As with functions in general, the quantity inside $\sin$ here is called an argument.