如果极限值存在，求极限值，若果不存在，说明理由，[tex=4.857x1.857]MhC0sa4kP8ihnFHLNuEHS4j9gRqVd06fVE9SZYdi3cw=[/tex] .

下列广义积分发散的是(   ) 未知类型：{'options': ['\xa0[tex=4.357x1.714]kB6ywHh1z8ag2v+SlC7MXGrZE0Ml3MfrzkImcv3bHlUp/fPUMAnDz9IgbGPk9izs[/tex]', '[tex=4.857x1.857]kB6ywHh1z8ag2v+SlC7MXLynKn/0bUj+aJjC2B3jJ2Qzf0v2Ng8YDo22UrEl5l2c[/tex]', '[tex=5.214x1.643]XyZcmlhqoYQGVTMuIZR3dvx/M4rEQHKOOro4reDyShwTC4VKb4PqDXostHwSd8TP[/tex]', '[tex=5.571x1.714]a6QQI3dVB3oF6DUxtXBB9Jd2MgOWxuRvTHZrFV/KOuoTTim8ph5plaj4f6JrsGtUlrgd4GIL0K0CNAulq8oF3g==[/tex]'], 'type': 102}

下列广义积分发散的是(   ) 未知类型：{'options': ['\xa0[tex=4.357x1.714]kB6ywHh1z8ag2v+SlC7MXGrZE0Ml3MfrzkImcv3bHlUp/fPUMAnDz9IgbGPk9izs[/tex]', '[tex=4.857x1.857]kB6ywHh1z8ag2v+SlC7MXLynKn/0bUj+aJjC2B3jJ2Qzf0v2Ng8YDo22UrEl5l2c[/tex]', '[tex=5.214x1.643]XyZcmlhqoYQGVTMuIZR3dvx/M4rEQHKOOro4reDyShwTC4VKb4PqDXostHwSd8TP[/tex]', '[tex=5.571x1.714]a6QQI3dVB3oF6DUxtXBB9Jd2MgOWxuRvTHZrFV/KOuoTTim8ph5plaj4f6JrsGtUlrgd4GIL0K0CNAulq8oF3g==[/tex]'], 'type': 102}

下列广义积分发散的是(   ) 未知类型：{'options': ['\xa0[tex=4.357x1.714]kB6ywHh1z8ag2v+SlC7MXGrZE0Ml3MfrzkImcv3bHlUp/fPUMAnDz9IgbGPk9izs[/tex]', '[tex=4.857x1.857]kB6ywHh1z8ag2v+SlC7MXLynKn/0bUj+aJjC2B3jJ2Qzf0v2Ng8YDo22UrEl5l2c[/tex]', '[tex=5.214x1.643]XyZcmlhqoYQGVTMuIZR3dvx/M4rEQHKOOro4reDyShwTC4VKb4PqDXostHwSd8TP[/tex]', '[tex=5.571x1.714]a6QQI3dVB3oF6DUxtXBB9Jd2MgOWxuRvTHZrFV/KOuoTTim8ph5plaj4f6JrsGtUlrgd4GIL0K0CNAulq8oF3g==[/tex]'], 'type': 102}

下列广义积分发散的是(   ) 未知类型：{'options': ['\xa0[tex=4.357x1.714]kB6ywHh1z8ag2v+SlC7MXGrZE0Ml3MfrzkImcv3bHlUp/fPUMAnDz9IgbGPk9izs[/tex]', '[tex=4.857x1.857]kB6ywHh1z8ag2v+SlC7MXLynKn/0bUj+aJjC2B3jJ2Qzf0v2Ng8YDo22UrEl5l2c[/tex]', '[tex=5.214x1.643]XyZcmlhqoYQGVTMuIZR3dvx/M4rEQHKOOro4reDyShwTC4VKb4PqDXostHwSd8TP[/tex]', '[tex=5.571x1.714]a6QQI3dVB3oF6DUxtXBB9Jd2MgOWxuRvTHZrFV/KOuoTTim8ph5plaj4f6JrsGtUlrgd4GIL0K0CNAulq8oF3g==[/tex]'], 'type': 102}

下列变量组（）是一个闭回路。 A: {x，x，x，x，x，x} B: {x，x，x，x，x} C: {x，x，x，x，x，x} D: {x，x，x，x，x，x}

以下谓词蕴含式正确的是（）: (∀x) (A(x)→B(x))=>( ∀x)A(x)→(∀x)B(x)|(∀x) (A(x)↔B(x))=>( ∀x)A(x)↔(∀x)B(x)|(∀x)A(x)∨(∀x)B(x)=>( ∀x) (A(x)∨B(x))|(∃x) (A(x)∧B(x))=>(∃x)A(x)∧(∃x)B(x)

以下谓词蕴含式正确的是（）: (?x) (A(x)→B(x))=>( ?x)A(x)→(?x)B(x)|(?x) (A(x)?B(x))=>( ?x)A(x)?(?x)B(x)|(?x)A(x)∨(?x)B(x)=>( ?x) (A(x)∨B(x))|(?x) (A(x)∧B(x))=>(?x)A(x)∧(?x)B(x)

下列式中错误的是： A: (∀x)(A(x)Úp(x)) Û (∀x)A(x)Ú (∀x)p(x) B: ($x)A(x) Ù p Û ($x)(A(x) Ù p ) C: (∀x)(A(x)ÚB(x)) Þ (∀x)A(x)Ú( ∀x)B(x) D: ($x)(A(x)ÙB(x)) Þ ($x)A(x)Ù( $x)B(x)

判断下列推证是否正确。 (∀x)(A(x)→B(x))⇔(∀x)(￢A(x)∨B(x)) ⇔(∀x)￢( A(x)∧￢B(x) ) ⇔￢(∃x) ( A(x)∧￢B(x) ) ⇔￢( (∃x)A(x)∧(∃x)￢B(x) ) ⇔￢(∃x)A(x)∨￢(∃x)￢B(x) ⇔￢(∃x)A(x)∨(∀x)B(x) ⇔(∃x)A(x)→(∀x)B(x)