When was Valentine supposedly executed? A: This was on February 14, 269 A.D.. B: This was on March 14, 269 A.D.. C: This was on July 7, 269 A.D.. D: This was on January 14, 269 A.D..

Ifsin<em>x</em>=7/25,thentan<em>x</em>=______. A: 7/20 B: 24/25 C: 7/24 D: 24/7 E: 8/24

3和48之间插入三个数x ，y，z，使这五个数成等比数列，则这三个数分别是( )． A: x=6，y=12，z=24 B: x=－6，y=12，z=－24 C: x=－6，y=－12，z=－24 D: x=6，y=12，z=24或x=－6，y=12，z=－24

某调幅波的频谱结构图如图所示,其时域表达式为[img=175x69]17e4385a29c82a2.jpg[/img] 未知类型：{'options': ['17e4385a338cd73.png(V)', ' [img=235x25]17e4385a3bce510.png[/img](V)', ' [img=269x24]17e4385a444d61a.png[/img](V)', ' [img=269x24]17e4385a4ccaebe.png[/img](V)'], 'type': 102}

下列语句的执行结果是True。 x = [24, 50, 37] y = 24 in x print(y)

执行语句int&#91;&#93;x=newint&#91;25&#93;；后，正确的说法是（） A: x[24]为0 B: x[24]未定义 C: x[25]为0 D: x[0]为空

执行完代码"int&#91;&#93;x=newint&#91;25&#93;;"后以下()说明正确的 A: x[24]为0 B: x[24]未定义 C: x[25]为0 D: x[0]为空

以4，9，1为为插值节点，求\(\sqrt x \)的lagrange的插值多项式 A: \( {2 \over {15}}(x - 9)(x - 1) + {3 \over {40}}(x - 4)(x - 1) + {1 \over {24}}(x - 4)(x - 9)\) B: \( - {2 \over {15}}(x - 9)(x - 1) + {3 \over {40}}(x - 4)(x - 1) + {1 \over {24}}(x - 4)(x - 9)\) C: \( - {2 \over {15}}(x - 9)(x - 1) + {3 \over {40}}(x - 4)(x +1) + {1 \over {24}}(x - 4)(x - 9)\) D: \( - {2 \over {15}}(x - 9)(x - 1) + {3 \over {40}}(x - 4)(x - 1) - {1 \over {24}}(x - 4)(x - 9)\)

十进制数269转换成十六进制数是

十进制数269转换成十六进制数是