what is f(x) for this function? regarding fourier series.

need help integrating Ak Bk and Ao to get signal in terms of freq domain

the pink is Ao integration, not sure how to integrate |t| if that is indeed f(x)sin ak​ = L1​ ∫ −LL​ f(x)cos(kπt)dt 2π1​ ∫ −ππ​ ∣t∣dt= 2π1​ 2+∣t∣​ ∣∣​ −ππ​ = 4π1​ (x+π∣+(−π)∣−π∣)= π 2 ​ = 2ππ 2

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