问题 选择题 函数y=1og2(x2+2)(x≤0)的反函数是( )A.y=2x+2(x≥0)B.y=-2x+2(x≥0)C.y=2x-2(x≥1)D.y=-2x-2(x≥1) 答案 ∵y=1og2(x2+2)(x≤0),∴x=-2y-2,且y≥1,∴函数y=1og2(x2+2)(x≤0)的反函数为y=-2x-2(x≥1).故选D.