In this article, let’s discuss how to subtract one polynomial to another. Two polynomials are given as input and the result is the subtraction of two polynomials.
- The polynomial p(x) = C3 x2 + C2 x + C1 is represented in NumPy as : ( C1, C2, C3 ) { the coefficients (constants)}.
- Let take two polynomials p(x) and q(x) then subtract these to get r(x) = p(x) – q(x) as a result of subtraction of two input polynomials.
If p(x) = A3 x2 + A2 x + A1 and q(x) = B3 x2 + B2 x + B1 then result is r(x) = p(x) - q(x) i.e; r(x) = (A3 - B3) x2 + (A2 - B2) x + (A1 - B1) and output is ( (A1 - B1), (A2 - B2), (A3 - B3) ).
In NumPy, it can be solved using the polysub() method. This function helps to find the difference of two polynomials and then returning the result as a polynomial
Below is the implementation with some examples :
Example 1: Using polysub()
Python3
# importing package import numpy # define the polynomials # p(x) = 5(x**2) + (-2)x +5 px = (5,-2,5) # q(x) = 2(x**2) + (-5)x +2 qx = (2,-5,2) # subtract the polynomials rx = numpy.polynomial.polynomial.polysub(px,qx) # print the resultant polynomial print(rx) |
Output :
[ 3. 3. 3.]
Example 2: sub_with_decimals
Python3
# importing package import numpy # define the polynomials # p(x) = 2.2 px = (0,0,2.2) # q(x) = 9.8(x**2) + 4 qx = (9.8,0,4) # subtract the polynomials rx = numpy.polynomial.polynomial.polysub(px,qx) # print the resultant polynomial print(rx) |
Output :
[-9.8 0. -1.8]
Example 3: #eval_then_sub
Python3
# importing package import numpy # define the polynomials # p(x) = (5/3)x px = (0,5/3,0) # q(x) = (-7/4)(x**2) + (9/5) qx = (-7/4,0,9/5) # subtract the polynomials rx = numpy.polynomial.polynomial.polysub(px,qx) # print the resultant polynomial print(rx) |
Output :
[ 1.75 1.66666667 -1.8 ]
