Why is the domain (-π,π) for 2sin(2x) if horizontal compression changes it?

[DethRose]

I have a question that says: prepare a table of values and plot the graph for the domain (-pie,pie) for the function f(x)=2sin(2x)

I understand how to do that for y=sinx, but for this function the wave compresses horizontally and stretches vertically so isn't the domain now (-pie/2,pie/2) and then therefore how can you make a table of values for (-pie,pie).

thanks for any help
andrew

 

[Dick]

No, the domain is still (-pi,pi). Just use a calculator.

 

[DethRose]

why is that because doesn't the 2x compress it horizontally?

 

[Dick]

Yes, the period will be cut in half, but you can still put x=pi, f(x)=2*sin(2*pi) in your table.

 

[HallsofIvy]

The period is now $[-\pi /2, \pi /2]$. The "domain" is still all real numbers just as it is for sin(x).