I am working with polynomials. I'd like to compute the symbolic derivative of a monomial with symbolic coefficients, that is something like
derivative(x^n,x)
So that the output is
nx^(n-1)
Is this possible?
Edit: My first try was of course to use:
diff(x^n,x)
or
derivative(x^n,x)
but I get the error
TypeError: non-integral exponents not supported
I'll continue my comment here so the code is clear. Go to a Sage cell server, such as here and copy paste the following code into the box:
var('n')
diff(x^n,x)
Press "Evaluate" and your output will be: nx^(n-1). Your question indicates that you tried diff(x^n,x) without declaring var('n'). Sage assumes x is a variable but everything else must be declared as a variable.
That's what dazedANDconfused suggested, don't know how you could get an error.
var('n')
f(x) = x^n
df = diff(f,x)
df
Asked: 2014-08-14 14:29:44 +0100
Seen: 726 times
Last updated: Aug 16 '14
Copyright Sage, 2010. Some rights reserved under creative commons license. Content on this site is licensed under a Creative Commons Attribution Share Alike 3.0 license.
Yes. First, type: var('n') This will tell Sage that n is a variable. Then type: diff(x^n,x) Run those two lines and you will get the output you want.
@dazedANDconfused : thanks, but that is the first thing I tried, as that method works with "number exponents". When I put the command I receive an error. I shall edit my question to reflect this.
@hildejk , I was able to run what @ndomes suggested below without error, using sage 6.3.