幂级数[图]的和是（）。A. xsinxB. [图]C. xln（1-x）D. xl...

A . 损耗率 B . 净料率 C . 成本率 D . 熟品率

A . A.10 B . B.14 C . C.7.5

A . 40 B . 42 C . 46 D . 51

A . 40 B . 42 C . 46 D . 51

A . xsinxB .https://assets.asklib.com/psource/20151030085351742.jpg C . xln（1-x）D . xln（1+x）

<img src='https://img2.soutiyun.com/ask/2020-12-22/977479103761578.png' />

A．0010 B．0100 C．1102 D．1110

试写出图题10-1所示方波的傅里叶级数。(利用教材图10-1(a)所示方波的傅里叶级数表示式。) <img src='https://img2.soutiyun.com/ask/2020-09-01/967820103151964.png' />

级数<img src='https://img2.soutiyun.com/shangxueba/ask/17673001-17676000/17675707/2015102616302484350.jpg' />（lgx）ⁿ的收敛区域是：（） A．（-1，1） B． （-10，10） C． （-1／10，1／10） D． （1／10，10）

函数<img src='https://img2.soutiyun.com/shangxueba/ask/17670001-17673000/17671257/2015102914165070741.jpg' />在x=2处的泰勒级数展开式为（）． A．<img src='https://img2.soutiyun.com/shangxueba/ask/17670001-17673000/17671257/2015102914171256962.jpg' /> B．<img src='https://img2.soutiyun.com/shangxueba/ask/17670001-17673000/17671257/2015102914172646978.jpg' /> C．<img src='https://img2.soutiyun.com/shangxueba/ask/17670001-17673000/17671257/2015102914174241489.jpg' /> D．<img src='https://img2.soutiyun.com/shangxueba/ask/17670001-17673000/17671257/2015102914180033916.jpg' />

<img src='https://img2.soutiyun.com/shangxueba/ask/17670001-17673000/17671947/2015102616370673553.jpg' />的傅立叶级数展开式中，系数a₃的值是：（） A. ['['π B. 1／10π（-1+）<img src='https://img2.soutiyun.com/shangxueba/ask/17670001-17673000/17671947/2015102616370717083.jpg' /> C. 1／10π（1+<img src='https://img2.soutiyun.com/shangxueba/ask/17670001-17673000/17671947/2015102616370717083.jpg' />） D. 1／10π（1-<img src='https://img2.soutiyun.com/shangxueba/ask/17670001-17673000/17671947/2015102616370717083.jpg' />）

将函数<img src='https://img2.soutiyun.com/shangxueba/ask/18747001-18750000/18749367/2016071617013646896.jpg' />，在［-π，π］上展开成傅里叶级数，其形式为<img src='https://img2.soutiyun.com/shangxueba/ask/18747001-18750000/18749367/2016071617014226431.jpg' />（）<img src='https://img2.soutiyun.com/shangxueba/ask/18747001-18750000/18749367/2016071617014996704.jpg' /> A．A B． B C． C D． D

若级数<img src='https://img2.soutiyun.com/shangxueba/ask/17670001-17673000/17671850/2015102616224486454.jpg' />a_n发散，<img src='https://img2.soutiyun.com/shangxueba/ask/17670001-17673000/17671850/2015102616224486454.jpg' />b_n发散，则有下列中何项结论（）？ A．<img src='https://img2.soutiyun.com/shangxueba/ask/17670001-17673000/17671850/2015102616224486454.jpg' />（a_n+b_n）发散 B．<img src='https://img2.soutiyun.com/shangxueba/ask/17670001-17673000/17671850/2015102616224486454.jpg' />_nb_n发散 C．<img src='https://img2.soutiyun.com/shangxueba/ask/17670001-17673000/17671850/2015102616224486454.jpg' />（a_n+b_n）收敛、发散不确定 D．<img src='https://img2.soutiyun.com/shangxueba/ask/17670001-17673000/17671850/2015102616224486454.jpg' />（a_n-b_n）收敛

A．损耗率 B．净料率 C．销售毛利率 D．熟品率

幂级数<img src='https://img2.soutiyun.com/shangxueba/ask/17661001-17664000/17661116/2016030117221193610.jpg' />的收敛域为（）。 A．（-2，2） B． ［-2，2） C． （-2，2] D． ［-2，2]

A．568 B． 497 C． 523 D． 491

<img src='https://img2.soutiyun.com/ask/2020-07-24/964447115529705.png' />