What is the Definition of Period in Fourier Series?

[CannonSLX]

Homework Statement

Homework Equations

The Attempt at a Solution

a0=4
an=8/Pi*n

Heres a written solution
https://gyazo.com/57e11d1e7a360914db8aec167beb6b39.png

 

[berkeman]

In the future, please be sure to UPLOAD images rather than use externally hosted links. Here is your solution UPLOADed:

 

[vela]

Strictly speaking, your answer for (i)(b) is wrong since you didn't state the period. Note the phrase "of period $2\pi$" in the problem statement for (ii). It's not a range of values for $x$. It's a number. What exactly is the definition of the term period?

If you want to check your answer for (ii), just plot the series.