trisection point

The centroid of a triangle is, by definition, the point of intersection of the three medians: moreover, it is a trisection point of each of the medians.

1959 [Doubleday], William R. Gondin, Bernard Sohmer, Intermediate Algebra & Analytic Geometry Made Simple, 1967, W. H. Allen, page 147, Find the trisection points of the line P_4P_5 in the same diagram.

1998, Paul J. Nahin, An Imaginary Tale: The Story of √, Princeton University Press, 2010, paperback, page 88, And if λ=2, then P is a trisection point of P_1P_2 and z=(z_1+2z_2)/3. Notice that this trisection point is closer to P_2 than it is to P_1. The other trisection point, the one that is closer to P_1 than it is to P_2, occurs for λ= tfrac 1 2, which gives z=(2z_1+z_2)/3.