The question: Let z1 and z2 be distinct complex numbers. Show that the locus of points z={tz1+(1−t)z2,−∞<t<∞}, describes the line through z1 and z2. The values $01 give the line segment joining z1 and z2.
I have an intuitive understanding of why the locus is a line, as it is similar to the description of a line through two points in R^2. However, I'm not sure how to prove this holds in C. Should I be trying to express it as one of the equations for line in C, such as Re(n̄z) = C or w̄z + wz̄ = r?