v_1(x) = sin(x)
v_2(x) = cos(x)
v_3(x) = (0.2 * x^(2)) - 2
v_4(x) = (0.1 * x^(3))
e(x) = (1 / 4 * (v_1(x) + v_2(x) + v_3(x) + v_4(x)))
v(x) = (0.25 * ((v_1(x) - e(x))^(2) + (v_2(x) - e(x))^(2) + (v_3(x) - e(x))^(2) + (v_4(x) - e(x))^(2)))
v_{+}(x) = e(x) + v(x)
v_{-}(x) = e(x) - v(x)