Differentiation in Python

[zingbagbamark]

How do I differentiate(first order and 2nd order) the following equations in python. I want to differentiate C wrt Q.

C = (Q**3)-15*(Q**2)+ 93*Q + 100

 

[Steven D'Aprano]

How do I differentiate(first order and 2nd order) the following
equations in python. I want to differentiate C wrt Q.

C = (Q**3)-15*(Q**2)+ 93*Q + 100

For such a simple case, you don't do it with Python, you do it with
maths, and get an exact result.

dC/dQ = 3*Q**2 - 30*Q + 93


d²C/dQ² = 6*Q - 30


The rule for differentiating polynomials of the form

y = k*x**n

is:

dy/dx = (k*n)*x**(n-1)

Consult a good calculus text book or on-line site for further details.

 

[David Robinow]

How do I differentiate(first order and 2nd order) the following equations in python. I want to differentiate C wrt Q.

C = (Q**3)-15*(Q**2)+ 93*Q + 100

"""
Years ago, when I actually worked for a living, I would have
done something like this:
"""
coeffs = [1, -15, 93, 100]
num_coeffs = len(coeffs)-1
deriv = [coeffs*(num_coeffs-i) for i in range(num_coeffs)]
print(deriv)

"""
The above is somewhat obscure and requires one to add
some documentation. Who wants to do that?

Below is a version using numpy. You get the numpy docs
for free.
"""
import numpy as np
p = np.poly1d(coeffs)
deriv_np = np.polyder(p)
print(deriv_np)
# or
print(list(deriv_np))