  In this paper, we determine the numb er of zeros and the zero inclusion
regions of a two-parameter family of harmonic quadrinomials. We also determine
a curve that separates sense-preserving and sense-reversing regions for these
families of quadrinomials. Our work makes practical and effective use of the
work of Wilmshurst, Khavinson, Dehmer, and also Bezouts theorem in the plane.

Complex Variables