# numpy.polysub#

numpy.polysub(a1, a2)[source]#

Difference (subtraction) of two polynomials.

Note

This forms part of the old polynomial API. Since version 1.4, the new polynomial API defined in numpy.polynomial is preferred. A summary of the differences can be found in the transition guide.

Given two polynomials a1 and a2, returns a1 - a2. a1 and a2 can be either array_like sequences of the polynomials’ coefficients (including coefficients equal to zero), or poly1d objects.

Parameters
a1, a2array_like or poly1d

Minuend and subtrahend polynomials, respectively.

Returns
outndarray or poly1d

Array or poly1d object of the difference polynomial’s coefficients.

Examples

$(2 x^2 + 10 x - 2) - (3 x^2 + 10 x -4) = (-x^2 + 2)$
>>> np.polysub([2, 10, -2], [3, 10, -4])
array([-1,  0,  2])