Linked Questions

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 ...
user avatar
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 ...
Bravyi's user avatar
  • 21
1 vote
2 answers
986 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: ...
NeonGabu's user avatar
  • 115
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....
Joao Alberto's user avatar
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 ...
Mikasa's user avatar
  • 211
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 ...
Dr. Wolfgang Hintze's user avatar
1 vote
1 answer
170 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 ...
Nikolaos Petropoulos's user avatar
0 votes
1 answer
182 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 ...
Benighted's user avatar
  • 1,327
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 (...
Mat6554's user avatar
  • 41
1 vote
0 answers
63 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 ...
kotozna's user avatar
  • 319