Linked Questions

2 votes
2 answers
218 views

Taking the derivative of Re[f]

I have looked at similar posts, such as this one, but none of the solutions have worked for me. I have an imaginary function, and I have tried to obtain its real part using ...
2 votes
1 answer
367 views

Can Mathematica help a theorem to be alive?

We are used to do limits by means of $\epsilon, \delta$. This is the first step an student encounters limits. Using $\epsilon$ and $\delta$ leads him to be familiar to Logic. I have taught limits and ...
1 vote
0 answers
61 views

ComplexExpand of Hypergeometric function

I would like to take the derivative of the absolute-squared value of a hypergeometric function and plot the result, for real arguments ...
1 vote
1 answer
168 views

Getting strange result with derivative of Abs of a complex number

So I am getting some results after a computation like: (-0.741446 - 5.47358 I) Abs'[-0.702207 + 0.0951203 I] The problem is the derivative in ...
1 vote
2 answers
982 views

Working with complex valued functions

I have a function which has real and imaginary parts and I need to differentiate both parts separately. This is a simpler example of what I have tried, without success: ...
4 votes
2 answers
720 views

Group delay of a transfer function

I'm trying to find a straightforward way to find the group delay of a transfer function. I've created a transfer function, and through the BodePlot function, I'm able to plot its phase characteristic....
0 votes
1 answer
180 views

Why is FindRoot failing to evaluate this function? [closed]

I have a (somewhat long) script which runs cleanly until the very last stage. Here, I'm using FindRoot to attempt to parameterize implicit curves in the zero set ...
4 votes
0 answers
179 views

How to take the second derivative of a complicated function using limits [closed]

I have a very complicated function of one variable consisting of exponential and error functions combined in various ways. Mathematica can't take the derivative of this function in the usual way (...
4 votes
0 answers
349 views

Strange behaviour of MMA in derivatives of some standard functions

There are some peculiar things to be discovered in derivatives of some standard functions in MMA: Strange behaviour Example 1: Abs We have ...
10 votes
2 answers
2k views

Simplifying the derivative of $|x|$

Context In[855]:= D[Abs[x], x] /. x -> 1 Out[855]= Derivative[1][Abs][1] In[856]:= D[x, x] /. x -> 1 Out[856]= 1 Question Why is ...