说明：  1. 连续和离散时间信号与系统的MATLAB表达及简要分析。 （1） 列出单位冲激函数、单位阶跃、复指数函数等连续信号的MATLAB表达式。 （2） 产生一个幅度为2，数字角频率为 ，相位为 的正弦序列。
(1. Continuous and discrete-time signals and systems and a brief analysis of MATLAB expression. (1) are listed in unit impulse function, unit step, complex exponential function, such as the MATLAB signal for expression. (2) produce a range of 2, the number of angular frequency for the sinusoidal phase sequence for.)