用对数求导法求函数[tex=6.643x2.929]jeGXNBpPqWfi9JH5CEZkzIsabNpoYZcxeVSslMXmujayax7fPi1zb3foWPKHpKGFcFsBpLiVkhzS6baYrWzmxw==[/tex]的导数。

若图所示电路中晶体管饱和管压降的数值为[tex=2.714x1.357]FsmOLMQIYzXN/74USWAV0RM+Lk9G1vdV1TmGa+yUZD8=[/tex]，则最大输出功[tex=2.643x1.214]V+d0WfKckPfdhDxnL9Tfig==[/tex][img=368x265]179757538448bfd.png[/img] 未知类型：{'options': ['[tex=5.929x2.786]vYcglVXUQkWOhgLYiiV7Ucjul/COkCoNui8HkmyvFY4JVq8MFAVztFuGkP1YcTeyMDdWs07ICEe+j0mFnwzu0g==[/tex]', '[tex=6.643x2.929]zj6Kg0qY+fhxMD0cykPfoz1xdejqbh8pRXGX15IB7B3yJQ5ycW7EZT7m2TYTlxHKl0DANw5d4jdvmrmWEXoa6g==[/tex]', '[tex=6.643x2.929]zj6Kg0qY+fhxMD0cykPfoz1xdejqbh8pRXGX15IB7B3yJQ5ycW7EZT7m2TYTlxHKivmvWSguwkWsMocfeR29ThjsT6HHzPldjvjMe4XvFsw=[/tex]'], 'type': 102}

求曲线[tex=6.643x2.929]7EJHVCtO2IWq3KpdB+jQsmQot3LOviCs8Sgxq1tsKFQ1asVGB0y5NsxwlDkUkh3DIxvJF6bo03H+sxzFkeBaH5LaHJPs6ADg29jpL1LqEKs=[/tex]绕[tex=0.5x0.786]gdMkE6SnyZedYLxpUxdkaQ==[/tex]轴旋转一周所生成的旋转曲面的方程.

[tex=6.286x2.786]jcCMHflCR8OS9TosV6N5vNj+EW06K/6o42LPtj1vNrdK+78XKAMo5J1AbKERG+qoTYjYEu96Pc/lsU360FcRow==[/tex][tex=27.643x2.786]ZGTtUfVHiJDAU4i+qE4bMsTWBqOPJkEidSsTjPewqRjxN81IY+bFIvQYkRhcoZ0+tX4Ndy3rKR6J0PrQ5aDr1Ta42BTzn/lv6MFkNMmnNXa/3gJUjL5Xx1rwfEZO9iG9Fre4o7jb+4K3/zhi+BSyle/KSYs6bwVQA3DOAgitc1l9spZLgms2TDSDSbziQXcCRtma9BVtUIcJko7k1HSda/NO5uxJiwQZTS+6qcDOtYXr9XsEemcZ+hDzgfNOpnERf87LSGzI1OiB6PZJNQrfI0qv+1GR42jd91k7cvl2MZlWnm388W0jwmp6wwtu/1U1n06GqVly57EK+2KWFAqBSnIrHJxiRwHeCoGyoqm+CmYmMfIqJkdFy4zKGvr370Hz[/tex][tex=5.429x2.786]ZGTtUfVHiJDAU4i+qE4bMjO4QIEh/CVqYF+NvXni/O/u2uwBBTl5zLKkpLHS9CkCrX0CCPoke8NVQDTiGzDzIQ==[/tex]计算[tex=6.643x2.929]jcCMHflCR8OS9TosV6N5vDk7hrRZvxF9hAel2hjeuXXrWWzl0bmuIJHdOXiPr8Ynfv7zFJRfPrr5bmYwySMT7TDc/RSoFl972rZKKFOLHyM=[/tex]。

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)

以下谓词公式中，( )不是逻辑有效式。 A: ($x)(P(x)∧Q(x)) Þ ($x) P(x)∧($x) Q(x) B: ("x)(P(x)∧Q(x)) Þ ("x) P(x)∧("x) Q(x) C: ($x)(P(x)∧Q(x)) Û ($x) P(x)∧($x) Q(x) D: ("x)(P(x)∧Q(x)) Û ("x) P(x)∧("x) Q(x)