Need to find Fourier series of the following graph

Need to find Fourier series of the following graph.....question is also written in figure.

• ...and you want to do this in Mathematica? Do you already have an expression for the function represented by the red graph? – J. M.'s technical difficulties Oct 20 '18 at 7:32
• 1) Yes...i want to find Find Fourier Series/Coefficients with Mathematica. – UTs Oct 20 '18 at 7:35
• 2) I dont have the expression for the function represented in red graph....want mathematica to find it – UTs Oct 20 '18 at 7:36
• That would help. – J. M.'s technical difficulties Oct 20 '18 at 7:46
• I am positive that you can build up the expression for the general Fourier coefficient from this simple integral: Integrate[Sin[\[Omega] t] Exp[I n t], {t, a, b}]. Pleas note that copyable code in Mathematica syntax is usually preferred over images. – Henrik Schumacher Oct 20 '18 at 8:00