What is sin 7x/4 ? i need on this urgent trig

If you start from the "standard" sine function, i.e.

You can change its graph in four ways:

Amplitude: you can multiply the whole function by a constant to stretch/squeeze it vertically. The transformation looks like

Phase: you can add a constant to the argument translate it horizontally. The transformation looks like

Period: you can multiply the argument by a constant to stretch/squeeze it horizontally. The transformation looks like

Shift: you can add a constant to the whole function to translate it vertically. The transformation looks like

In your case, we're changing the period of the function. If the function is squeezed, so you're squeezing the graph horizontally by a factor of 7/4

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step-by-step explanation: