Figure 3.

Panel (a) presents the normalized tumor density, while panel (b) displays the therapeutic dose using parameter values of r = 0.3 (growth rate) and δ = 0.45 (magnitude of the dose) for Equation (6). Depicted is the solution of the model without treatment (black) as well as the optimal control solutions for different combinations of weights. The weights depicted are: (w₁, w₂, w₃) = (1,1,1) (red), increased weight on the tumor density at the final time (w₁, w₂, w₃) = (3,1,1) (blue), increased weight on the tumor density over the whole treatment (w₁, w₂, w₃) = (1, 3, 1) (green), and increased weight on the therapy toxicity (w₁, w₂, w₃) = (1, 1, 3) (purple). By varying the weights in the optimal control functional, tumor control can vary, and the recommended drug dosage may increase or decrease over time.