7.1 Objects
As we saw in section 5.6, Python does not have a built-in object that implements polynomials like
![Example of a polynomial](https://static.packt-cdn.com/products/9781801077859/graphics/Images/w-13-polynomial-object-example-gen.jpg)
You can import them from sympy or other packages, but we implement a simple version of them in this chapter.
In this example polynomial, x is an indeterminate, and it is the only indeterminate that appears in the polynomial. We call such a polynomial univariate (“one variable”).
We evaluate a polynomial by substituting a value for x and performing the algebra. For this reason, we can think of a polynomial as a function.
def p(x):
return x**3 - 5*x**2 + 7*x + 1
[p(x) for x in range(-2, 4)]
[-41, -12, 1, 4, 3, 4]
![Plot of the univariate polynomial x**3 - 5 * x**2 + 7 * x + 1](https://static.packt-cdn.com/products/9781801077859/graphics/Images/w-20-unipoly-plt.jpg)
In our definition of p
, there are four coefficients: 1, –5, 7, and
1. These are the explicit or implicit numbers
...