Formula:
$$f(x) = (1 + (x_1 + x_2 + 1)^2(19 - 14x_1 + 3x_1^2 - 14x_2 + 6x_1 x_2 + 3x_2^2))
\times (30 + (2x_1 - 3x_2)^2(18 - 32x_1 + 12x_1^2 + 48x_2 - 36x_1 x_2 + 27x_2^2))$$
Global minimum: \(f(0, -1) = 3\)
Characteristics:
The Goldstein-Price function has a complex landscape with the global
minimum surrounded by local minima of increasing value.