7 Error Functions, Dawson’s and Fresnel IntegralsProperties

§7.5 Interrelations

7.5.1 F⁡(z)=12⁢i⁢π⁢(e−z2−w⁡(z))=−12⁢i⁢π⁢e−z2⁢erf⁡(i⁢z).
7.5.2 C⁡(z)+i⁢S⁡(z)=12⁢(1+i)−ℱ⁡(z).
7.5.4 S⁡(z)=12−f⁡(z)⁢cos⁡(12⁢π⁢z2)−g⁡(z)⁢sin⁡(12⁢π⁢z2).

In (7.5.8)–(7.5.10)

7.5.7 ζ=12⁢π⁢(1∓i)⁢z,

and either all upper signs or all lower signs are taken throughout.

7.5.8 C⁡(z)±i⁢S⁡(z)=12⁢(1±i)⁢erf⁡ζ.
7.5.10 g⁡(z)±i⁢f⁡(z)=12⁢(1±i)⁢eζ2⁢erfc⁡ζ.
7.5.11 |ℱ⁡(x)|2=f2⁡(x)+g2⁡(x),
x≥0,
7.5.12 |ℱ⁡(x)|2=2+f2⁡(−x)+g2⁡(−x)−2⁢2⁢cos⁡(14⁢π+12⁢π⁢x2)⁢f⁡(−x)−2⁢2⁢cos⁡(14⁢π−12⁢π⁢x2)⁢g⁡(−x),
x≤0.

See Figure 7.3.4.

For Ei⁡(x) see §6.2(i).