Let f and g be continuous functions on [-20, 20] such that f(-x) = f(x), g(-x) = -g(x), and g(x) = 1 + f(x)·f(-x). If \(\int_{-20}^{20} f(x)\,dx = 2020\), then \(I = \int_{-20}^{20} \dfrac{f(x)}{g(x)}\,dx\) equals:
If \(I_1 = \int_{0}^{1} 2x^2 \, dx\), \(I_2 = \int_{0}^{1} 2x^3 \, dx\), \(I_3 = \int_{1}^{2} 2x^2 \, dx\) and \(I_4 = \int_{1}^{2} 2x^3 \, dx\), then