Use the Error Bound to find the least possible value of N for which Error(SN) ≤ 1 × 10^(-9) in approximating ∫10^6 e^(x^2) dx using the result that Error(SN) ≤ K4(b - a)^5 / (180N^4), where K4 is the least upper bound for all absolute values of the fourth derivatives of the function 6e^(x^2) on the interval [a, b].
N =