Re: How to plot derivative directly?
- To: mathgroup at smc.vnet.net
- Subject: [mg118079] Re: How to plot derivative directly?
- From: Richard Hofler <rhofler at bus.ucf.edu>
- Date: Tue, 12 Apr 2011 05:54:29 -0400 (EDT)
Hello Jakub,
In[9]:= deriv=D[x^3-6 (x+1)^2+x-7,x];
plot1 = Plot[deriv,{x,-3,8}]
An alternative method with Evaluate inserted:
In[11]:= plot2 = Plot[Evaluate[D[x^3-6 (x+1)^2+x-7,x]],{x,-3,8}]
The two plots are the same.
In[12]:= plot1==plot2
Out[12]= True
Richard Hofler
________________________________________
From: =8Aer=FDch Jakub [Serych at panska.cz]
Sent: Monday, April 11, 2011 7:05 AM
To: mathgroup at smc.vnet.net
Subject: [mg118079] [mg118061] How to plot derivative directly?
Dear mathgroup,
it seems to me, that response to my question shall be very simple,
but I cannot find it. :-(
I want to plot the derivative of the function. I would like to do it
directly, something like:
Plot[D[x^3 - 6 (x + 1)^2 + x - 7, x],{x,-3,8}]
It returns: General::ivar: "-2.99978 is not a valid variable."
I can understand that it is because local variable x from Plot command
interferes with the x variable from the D[].
Yes I can bypass the problem by:
deriv = D[x^3 - 6 (x + 1)^2 + x - 7, x]
Plot[deriv, {x, -3, 8}]
which is fully functional, but as far as I know Mathematica, there must
be some simple solution how to do it directly inside the Plot[].
Thanks in advance for kick-off
Jakub