题目2.[单选题] 信号f(t)=cos2t+sin3t周期为()A. πB. 2π/3C. 2πD. 6π2.[单选题] 信号f(t)=cos2t+sin3t周期为()A. πB. 2π/3C. 2πD. 6π题目解答答案C. 2π