直接证明与间接证明课后练习用三段论方法证明:2222222()abbccaabc≥.已知,,abcR,且236abc,求证:2222391357abcabc.已知abc,且0abc,求证:23baca.已知,,abcR,求证:22233abcab...
时间:2024-10-08 18:30栏目:中学教育