设a>1,0

设a>1,0 设a>1,0 设a>b>0,求证1/a (1/2)设a>0,|x| 设a>0,0 设a>0,0 设a>0,0 设a>0,0 设0＜a 设0〈a 设0≤a 设a>0,b 设0≤a 设0≤a 设0≤a 设a>0,b 1,设a 1、设a