【简答题】New words: Candid: adj. 诚实的,坦率的,正直的 The Telegraph 《电讯报》(英国) Throne n. 王位,帝位,王权,君权 Podcast n. 博客(一种可供下载的多媒体数字文件) 1.The best choice is 1. A. Because he had a terrible interview with the newspaper The Te...
【简答题】判断下列信号是否是周期信号,若是,求周期。要求仿照PPT中所讲解的例题那样写出过程,写在纸上拍照上传。 (1)f 1 ( t ) = sin2π t + cos3π t ? (2)f 2 ( t ) = tan t + cos2 t ? (提示: 注意正切函数与正弦函数的周期不同 ) (3)f 3 ( k ) = sin2π k + cos3π k ? (4)f 4 ( k ) = tan k +...