Formulas to calculate the coordinates Δx and y_o of the intersection O
of two curves y = f (x) and y_c = f (x), given the ordinates of two (2) points per curve, located near the intersection, with one abscissa at x₁, to the left of point O, and the other abscissa at x₂, to the right of point O:
y₁ = f (x₁); y₂ = f (x₂); y_c1 = f (x₁); and y_c2 = f (x₂)

The accuracy of the calculation increases with decreasing value of the interval x₂ - x₁.