對任意實(shí)數(shù)x，已知偶函數(shù)f(x)都滿足f(x＋2)＝f(x)，且當(dāng)2≤x≤3時(shí)，f(x)＝x，則當(dāng)－2≤x≤0時(shí)，f(x)的表達(dá)式為________