求log1/2√x2-6x+8>1的定义域.
依题意,有 {x2-6x+8≥0 {√x2-6x+8>0 {√x2-6x+8<1/2 即 {x26x+8>0 {x2-6x+31/4<0 即 {x>4或x<2 {(6-√5)/2<x<(6+√5)/2 所以 定义域为(6-√5)/2<x<2或4<x<(6+√5)/2.
求log1/2√x2-6x+8>1的定义域.
依题意,有 {x2-6x+8≥0 {√x2-6x+8>0 {√x2-6x+8<1/2 即 {x26x+8>0 {x2-6x+31/4<0 即 {x>4或x<2 {(6-√5)/2<x<(6+√5)/2 所以 定义域为(6-√5)/2<x<2或4<x<(6+√5)/2.