Derivative of a function with constants

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Georgios Markoulis
Georgios Markoulis on 13 Jan 2022
Edited: Torsten on 14 Jan 2022
Hello,
how can i calculate the derivative of a function like x*e^x(a*x^2+b*x+c), where a,b,c are constants(for example integers).
I tried syms x a b c and then
f=inline('ax^2+bx+c','x')
diff(f(x),x)
but then i get an error.
A function like that is easy enough without Matlab but i want the sum of y'''+y''-y'+y which needs a lot of calculation.
Thanks in advance.
  1 Comment
jessupj
jessupj on 13 Jan 2022
maybe
a*x^2 + b*x +c
with multiplication operations? (always report details of the error... its easier to tell what the problem is that way)

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Answers (1)

Torsten
Torsten on 13 Jan 2022
syms x a b c
f = x*e^x*(a*x^2+b*x+c);
df = diff(f,x)
  4 Comments
Torsten
Torsten on 14 Jan 2022
d2f = diff(f,x,2)
d3f = diff(f,x,3)
...
dnf = diff(f,x,n) % n-th derivative, n has to be set to a value before

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