S_0 = 9000 (slider from -5 to 10000, step 0.1)
I_0 = 1 (slider from -5 to 5, step 0.1)
β = 1.5E-4 (slider from -5 to 5, step 0.1)
γ = 0.7441 (slider from -5 to 5, step 0.1)
S'(x, S, I, R) = (((-β) * S) * I)
I'(x, S, I, R) = ((β * S) * I) - (γ * I)
R'(x, S, I, R) = (γ * I)
numericalIntegral1, numericalIntegral2, numericalIntegral3 = NSolveODE({S', I', R'}, 0, {S_0, I_0, 0}, 32)
R_0: (S_0 * β / γ)
v: 1 - 1 / R_0