G92 X Z F 指令中“X_Z ”定义的是螺纹加工的长度
G92 X Z F 指令中“X_Z ”定义的是螺纹加工的长度
【单选题】求点(x,y,z)关于原点和x轴,y轴,z轴的对称点坐标分别为 A. (-x,-y,-z),(x,-y,-z),(x,-y,z),(x,y,-z), B. (-x,-y,-z),(-x,y,z),(x,y,-z),(x,y,-z) C. (-x,-y,-z),(-x,-y,z),(x,-y,-z),(-x,y,-z) D. (-x,-y,-z),(x,-y,-z),(-x,y,-z),(-x,-y,z)
【单选题】求点(x,y,z)关于原点和x轴,y轴,z轴的对称点坐标分别为 A. (-x,-y,-z),(x,-y,-z),(x,-y,z),(x,y,-z), B. (-x,-y,-z),(-x,y,z),(x,y,-z),(x,y,-z) C. (-x,-y,-z),(-x,-y,z),(x,-y,-z),(-x,y,-z) D. (-x,-y,-z),(x,-y,-z),(-x,y,-z),(-x,-y,z)
以下哪几项是前束范式? A: (∀x)(∀y)(P(x)∧(∃z)Q(y,z)∨R(x,z)) B: (∀z)(∀x)(∃y)(P(x)∧Q(y,z)∨R(x,z)) C: (∀x)(∀y)(P(x)∧Q(y,z)∨(∃z)R(x,z)) D: (∃x)(∃y)(∀z)(P(x)∧Q(y,z)∨R(x,z))
以下哪几项是前束范式? A: (∀x)(∀y)(P(x)∧(∃z)Q(y,z)∨R(x,z)) B: (∀z)(∀x)(∃y)(P(x)∧Q(y,z)∨R(x,z)) C: (∀x)(∀y)(P(x)∧Q(y,z)∨(∃z)R(x,z)) D: (∃x)(∃y)(∀z)(P(x)∧Q(y,z)∨R(x,z))
【单选题】已知序列x(n)的双边z变换为X(z),收敛域|z|>|a|,则x(-n)的双边z变换和收敛域为() A. X(-z),|z|>|a B. X(1/z),|z|>1/|a| C. X(1/z),|z|<1/|a| D. X(-z),|z|
【单选题】已知序列x(n)的双边z变换为X(z),收敛域|z|>|a|,则x(-n)的双边z变换和收敛域为() A. X(-z),|z|>|a B. X(1/z),|z|>1/|a| C. X(1/z),|z|<1/|a| D. X(-z),|z|
已知()x()(()n())()的()z()变换是()X()(()z())(),()ROC()是()|()z()|()>()a(),则()x(()-()n()-()5())()的()z()变换和()ROC()是()()A.()()z()-()5()X()(1/()z()),z()>()1/()a()B.()()z()5()X()(1/()z()),z()>()1/()a()C.()()z()-()5()X()(1/()z()),z()<()1/()a()D.()()z()5()X()(1/()z()),z()<()1/()a
已知()x()(()n())()的()z()变换是()X()(()z())(),()ROC()是()|()z()|()>()a(),则()x(()-()n()-()5())()的()z()变换和()ROC()是()()A.()()z()-()5()X()(1/()z()),z()>()1/()a()B.()()z()5()X()(1/()z()),z()>()1/()a()C.()()z()-()5()X()(1/()z()),z()<()1/()a()D.()()z()5()X()(1/()z()),z()<()1/()a
设方程\({x^2} + {y^2} + {z^2} = 2Rx\)确定函数\(z=z(x,y)\),则\( { { \partial z} \over {\partial x}}=\) A: \( { { \partial z} \over {\partial x}} = { { R +x} \over z}\) B: \( { { \partial z} \over {\partial x}} =- { { R +x} \over z}\) C: \( { { \partial z} \over {\partial x}} = { { R - x} \over z}\) D: \( { { \partial z} \over {\partial x}} =- { { R - x} \over z}\)
设方程\({x^2} + {y^2} + {z^2} = 2Rx\)确定函数\(z=z(x,y)\),则\( { { \partial z} \over {\partial x}}=\) A: \( { { \partial z} \over {\partial x}} = { { R +x} \over z}\) B: \( { { \partial z} \over {\partial x}} =- { { R +x} \over z}\) C: \( { { \partial z} \over {\partial x}} = { { R - x} \over z}\) D: \( { { \partial z} \over {\partial x}} =- { { R - x} \over z}\)
55.与x * = y + z等价的赋值表达式是: A: x = y + z B: x = x * y + z C: x = x * (y + z) D: x = x + y * z
55.与x * = y + z等价的赋值表达式是: A: x = y + z B: x = x * y + z C: x = x * (y + z) D: x = x + y * z
对于关系模式R(X,Y,Z),下列结论错误的是() A: 若X→Y,Y→Z,则X→Z B: 若X→Y,X→Z,则X→YZ C: 若X→Z,则XY→Z D: 若XY→Z,则X→Z,Y→Z
对于关系模式R(X,Y,Z),下列结论错误的是() A: 若X→Y,Y→Z,则X→Z B: 若X→Y,X→Z,则X→YZ C: 若X→Z,则XY→Z D: 若XY→Z,则X→Z,Y→Z
数控车床回参考点顺序( ) A: +X→+Y→+Z B: -X→+Z C: +X→+Z D: +Z→+X
数控车床回参考点顺序( ) A: +X→+Y→+Z B: -X→+Z C: +X→+Z D: +Z→+X
公式"x ( F(x,y,z ) → "y ( G(x,y,z) → "z H(x,y,z) ) )的前束范式为 A: "x$y$z (F(x,t,w) → ( G(x,y,w ) → H(x,y,z) ) ) B: $x$y$z (F(x,t,w) → ( G(x,y,w ) → H(x,y,z) ) ) C: "x"y$z (F(x,t,w) → ( G(x,y,w ) → H(x,y,z) ) ) D: "x$y"z (F(x,t,w) → ( G(x,y,w ) → H(x,y,z) ) )
公式"x ( F(x,y,z ) → "y ( G(x,y,z) → "z H(x,y,z) ) )的前束范式为 A: "x$y$z (F(x,t,w) → ( G(x,y,w ) → H(x,y,z) ) ) B: $x$y$z (F(x,t,w) → ( G(x,y,w ) → H(x,y,z) ) ) C: "x"y$z (F(x,t,w) → ( G(x,y,w ) → H(x,y,z) ) ) D: "x$y"z (F(x,t,w) → ( G(x,y,w ) → H(x,y,z) ) )