问题 填空题 若函数f(x)=f(x+2),(x<2)log2x,(x≥2),则f(-4)=______. 答案 ∵f(x)=f(x+2),(x<2)log2x,(x≥2)∴f(-4)=f(-2)=f(0)=f(2)=log22=1故答案为 1