要求：从x(t)=sin(2*pi*5*t)+sin(2*pi*200*t)+sin(2*pi*50*t)信号中滤出频率为5Hz的信号-Requirements: from x (t) = sin (2* pi* 5* t)+ sin (2* pi* 200* t)+ sin (2* pi* 50* t) signal to filter out the signal frequency of 5Hz