High Accurate Simple Approximation of Normal Distribution Integral

Figure 4

(a) Cumulative distribution function (4.1) and approximations (4.3) and (4.5). (b) Relative error for each approximation 𝑥∈[−3,0]. (c) Relative error for each approximation 𝑥∈[0,4].

(a)

(b)

(c)