Answer :

Given,

[tex]y=-2\sin (\frac{2\pi x}{5})[/tex]

To find the period,

[tex]\begin{gathered} y=-2\sin (\frac{2\pi x}{5}) \\ y=A\sin (Bx-c)+D \end{gathered}[/tex]

Then, the period is,

[tex]\begin{gathered} =\frac{2\pi}{B} \\ =\frac{2\pi}{\pi} \\ =2 \end{gathered}[/tex]

Thus the period is 2