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Student Support Forum: 'derivative of amplitude-frequency characteristic' topicStudent Support Forum > General > Archives > "derivative of amplitude-frequency characteristic"

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Author Comment/Response
Bill Simpson
02/05/13 6:43pm

In[1]:= sys=s/(1000+s);
ampl=Abs[sys/.{s->2*Pi*f*I}]

Out[2]= 2*Pi*Abs[f/(1000 + (2*I)*f*Pi)]

In[3]:= D[ampl,f]

Out[3]= 2*Pi*(((-2*I)*f*Pi)/(1000 + (2*I)*f*Pi)^2 + (1000 + (2*I)*f*Pi)^(-1))*Abs'[f/(1000 + 2*I)*f*Pi)]

What do you want the derivative of Abs of a complex value to be? What is Abs'[3/I] for example? When you can decide that then perhaps a function can be found that will provide you Real values for a plot.

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Subject (listing for 'derivative of amplitude-frequency characteristic')
Author Date Posted
derivative of amplitude-frequency characteristic devil 02/05/13 2:19pm
Re: derivative of amplitude-frequency character... Bill Simpson 02/05/13 6:43pm
Re: Re: derivative of amplitude-frequency chara... devil 02/06/13 2:22pm
Re: Re: Re: derivative of amplitude-frequency c... Bill Simpson 02/06/13 8:25pm
Re: Re: Re: Re: derivative of amplitude-frequen... devil 02/07/13 1:08pm
Re: derivative of amplitude-frequency character... devil 02/20/13 07:16am
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