3D confidence ellipsoid (1σ, 2σ, and 3σ) for the parameters space (a₂, a₃, and a₄) and the corresponding 2D projections on panels a₂ − a₃, a₂ − a₄, and a₃ − a₄ from the SN-Q sample using the log(1 + z) method. The solid orange line shows the relation between two and three parameters in the log(1 + z) model. In 2D projections, red and black points correspond to Ω_m = 0.30 and Ω_m = 0.40, respectively. In the 3D confidence ellipsoid, the purple point corresponds to Ω_m = 0.30.