求 [tex=12.286x2.786]KRfj3G10JzzkQZWmVgXDF9EZdpAa7MWguoqzZoa4CjVdobwUJaO26Yr1WGW7HS9qobjkDTwK8k8DgT6+bu7cng==[/tex] 其中 [tex=19.429x3.357]72YwY1v17IOM9Fxyttt1lwSAfdMVZb6GixiTExHJzAApiPZDsJD/o7UYj6Nt4mpWpA9csqCt4xwi+tVGfOb0KJWAr4Zu4siBs8FeCv5jgPUn4JuXULaRLdUhSE/Ixv30vPUqUWY69qZIzS0SSYx9ZPd6+nVnqIHDY3oyws1otXA5O3vbNWrEhKllzH+m2kK7[/tex]
求 [tex=12.286x2.786]KRfj3G10JzzkQZWmVgXDF9EZdpAa7MWguoqzZoa4CjVdobwUJaO26Yr1WGW7HS9qobjkDTwK8k8DgT6+bu7cng==[/tex] 其中 [tex=19.429x3.357]72YwY1v17IOM9Fxyttt1lwSAfdMVZb6GixiTExHJzAApiPZDsJD/o7UYj6Nt4mpWpA9csqCt4xwi+tVGfOb0KJWAr4Zu4siBs8FeCv5jgPUn4JuXULaRLdUhSE/Ixv30vPUqUWY69qZIzS0SSYx9ZPd6+nVnqIHDY3oyws1otXA5O3vbNWrEhKllzH+m2kK7[/tex]
图示压杆体系中，弹簧支座刚度为[img=64x44]180379b3117202b.png[/img]，则该体系的临界荷载为kl的（ ）倍。[img=3924x1660]180379b32884d13.jpg[/img] A: 0.411 B: 1 C: 1.645 D: 3.357
图示压杆体系中，弹簧支座刚度为[img=64x44]180379b3117202b.png[/img]，则该体系的临界荷载为kl的（ ）倍。[img=3924x1660]180379b32884d13.jpg[/img] A: 0.411 B: 1 C: 1.645 D: 3.357
图示压杆体系中，弹簧支座刚度为[img=64x44]1802df48734317e.png[/img]，则该体系的临界荷载为kl的（ ）倍。[img=3924x1660]1802df4888c0309.jpg[/img] A: 0.411 B: 1 C: 1.645 D: 3.357
图示压杆体系中，弹簧支座刚度为[img=64x44]1802df48734317e.png[/img]，则该体系的临界荷载为kl的（ ）倍。[img=3924x1660]1802df4888c0309.jpg[/img] A: 0.411 B: 1 C: 1.645 D: 3.357
给定连续时间线性时变系统为[tex=19.429x3.357]dPjSc0wKi8UWADEN7une4wiMbow1uWECK0zzqSiBWD3WXVbbRGO67iYNlU4V+wM4n451mrGwhomyjUnfx2fbMsLqKK4qdWOeGhWP/UkttIn/aErv6qAjrMHudFYaK1AC8DArCM29T4PTwHxyRS1HPtBObOK+rc69gFG4pJex3q7x9FWzZZ5FCMDRCN6RRznkTY5uPQlWf3WBorC8PRTQnPs0iyMKnkZi+dog6cHhGi5SIp8K1h/iuVQlyYewPOKe[/tex],表系统状态转移矩阵为[tex=14.786x3.357]G2ufZMQNLiy/Wf3ObJUGu43vdCjrG71ZvDdcpeizWTXP8AfPlQLgIDLqOFTt9qf/9tqW6bs3h1qHEEMEIw1MvGb1j3jQ50ztlnmQTynTzZCuLDvPhqvgIYfH+VcPzo17j/SjBvDqUpkqrQwlvyEWo/Tb/E2+155xWpJljSQpBgOLrYorFUww+TDsDTgR0WXa0wQO1ndsjTpEDuMSRYa3vtZJuHiMrSPGqR2bk69dVaSCkjg7oKD15cXHUxZcP4/MErAnFrH3dkX89vQlRVRkcQ==[/tex],试证明:若[tex=3.929x1.357]jOaZ3X55nJ46mEA0Yqzh5reJPP1+ntTGtn/7sSUOEi8=[/tex],则必有[tex=5.214x1.357]UnCb4Q2nyy+u+PvXt+iroJrp1oJl7Dg8OXq+ZlZoAuMOn++1v9ZoIX5E/q5MVpNE[/tex]
给定连续时间线性时变系统为[tex=19.429x3.357]dPjSc0wKi8UWADEN7une4wiMbow1uWECK0zzqSiBWD3WXVbbRGO67iYNlU4V+wM4n451mrGwhomyjUnfx2fbMsLqKK4qdWOeGhWP/UkttIn/aErv6qAjrMHudFYaK1AC8DArCM29T4PTwHxyRS1HPtBObOK+rc69gFG4pJex3q7x9FWzZZ5FCMDRCN6RRznkTY5uPQlWf3WBorC8PRTQnPs0iyMKnkZi+dog6cHhGi5SIp8K1h/iuVQlyYewPOKe[/tex],表系统状态转移矩阵为[tex=14.786x3.357]G2ufZMQNLiy/Wf3ObJUGu43vdCjrG71ZvDdcpeizWTXP8AfPlQLgIDLqOFTt9qf/9tqW6bs3h1qHEEMEIw1MvGb1j3jQ50ztlnmQTynTzZCuLDvPhqvgIYfH+VcPzo17j/SjBvDqUpkqrQwlvyEWo/Tb/E2+155xWpJljSQpBgOLrYorFUww+TDsDTgR0WXa0wQO1ndsjTpEDuMSRYa3vtZJuHiMrSPGqR2bk69dVaSCkjg7oKD15cXHUxZcP4/MErAnFrH3dkX89vQlRVRkcQ==[/tex],试证明:若[tex=3.929x1.357]jOaZ3X55nJ46mEA0Yqzh5reJPP1+ntTGtn/7sSUOEi8=[/tex],则必有[tex=5.214x1.357]UnCb4Q2nyy+u+PvXt+iroJrp1oJl7Dg8OXq+ZlZoAuMOn++1v9ZoIX5E/q5MVpNE[/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}
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)
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( $x)B(x)
下列式中错误的是： A: (∀x)(A(x)Úp(x)) Û (∀x)A(x)Ú (∀x)p(x) B: ($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( $x)B(x)
判断下列推证是否正确。 (∀x)(A(x)→B(x))⇔(∀x)(￢A(x)∨B(x)) ⇔(∀x)￢( A(x)∧￢B(x) ) ⇔￢(∃x) ( A(x)∧￢B(x) ) ⇔￢( (∃x)A(x)∧(∃x)￢B(x) ) ⇔￢(∃x)A(x)∨￢(∃x)￢B(x) ⇔￢(∃x)A(x)∨(∀x)B(x) ⇔(∃x)A(x)→(∀x)B(x)
判断下列推证是否正确。 (∀x)(A(x)→B(x))⇔(∀x)(￢A(x)∨B(x)) ⇔(∀x)￢( A(x)∧￢B(x) ) ⇔￢(∃x) ( A(x)∧￢B(x) ) ⇔￢( (∃x)A(x)∧(∃x)￢B(x) ) ⇔￢(∃x)A(x)∨￢(∃x)￢B(x) ⇔￢(∃x)A(x)∨(∀x)B(x) ⇔(∃x)A(x)→(∀x)B(x)
以下谓词公式中，( )不是逻辑有效式。 A: ($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)∧($x) Q(x) D: ("x)(P(x)∧Q(x)) Û ("x) P(x)∧("x) Q(x)
以下谓词公式中，( )不是逻辑有效式。 A: ($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)