7.1 Special Notation7.3 Graphics

§7.2 Definitions

Contents

§7.2(i) Error Functions

7.2.1\mathop{\mathrm{erf}\/}\nolimits z=\frac{2}{\sqrt{\pi}}\int _{0}^{z}e^{{-t^{2}}}dt,
7.2.2\mathop{\mathrm{erfc}\/}\nolimits z=\frac{2}{\sqrt{\pi}}\int _{z}^{{\infty}}e^{{-t^{2}}}dt=1-\mathop{\mathrm{erf}\/}\nolimits z,
7.2.3\mathop{w\/}\nolimits\!\left(z\right)=e^{{-z^{2}}}\left(1+\frac{2i}{\sqrt{\pi}}\int _{0}^{z}e^{{t^{2}}}dt\right)=e^{{-z^{2}}}\mathop{\mathrm{erfc}\/}\nolimits\!\left(-iz\right).

\mathop{\mathrm{erf}\/}\nolimits z, \mathop{\mathrm{erfc}\/}\nolimits z, and \mathop{w\/}\nolimits\!\left(z\right) are entire functions of z, as is \mathop{F\/}\nolimits\!\left(z\right) in the next subsection.

Values at Infinity

7.2.4
\lim _{{z\to\infty}}\mathop{\mathrm{erf}\/}\nolimits z=1,
\lim _{{z\to\infty}}\mathop{\mathrm{erfc}\/}\nolimits z=0, |\mathop{\mathrm{ph}\/}\nolimits z|\leq\tfrac{1}{4}\pi-\delta(<\tfrac{1}{4}\pi).

§7.2(ii) Dawson’s Integral

7.2.5\mathop{F\/}\nolimits\!\left(z\right)=e^{{-z^{2}}}\int _{0}^{z}e^{{t^{2}}}dt.

§7.2(iii) Fresnel Integrals

7.2.6\mathop{\mathcal{F}\/}\nolimits\!\left(z\right)=\int _{z}^{\infty}e^{{\frac{1}{2}\pi it^{2}}}dt,
7.2.7\mathop{C\/}\nolimits\!\left(z\right)=\int _{0}^{z}\mathop{\cos\/}\nolimits\!\left(\tfrac{1}{2}\pi t^{2}\right)dt,
7.2.8\mathop{S\/}\nolimits\!\left(z\right)=\int _{0}^{z}\mathop{\sin\/}\nolimits\!\left(\tfrac{1}{2}\pi t^{2}\right)dt,

\mathop{\mathcal{F}\/}\nolimits\!\left(z\right), \mathop{C\/}\nolimits\!\left(z\right), and \mathop{S\/}\nolimits\!\left(z\right) are entire functions of z, as are \mathop{\mathrm{f}\/}\nolimits\!\left(z\right) and \mathop{\mathrm{g}\/}\nolimits\!\left(z\right) in the next subsection.

Values at Infinity

7.2.9
\lim _{{x\to\infty}}\mathop{C\/}\nolimits\!\left(x\right)=\tfrac{1}{2},
\lim _{{x\to\infty}}\mathop{S\/}\nolimits\!\left(x\right)=\tfrac{1}{2}.

§7.2(iv) Auxiliary Functions

7.2.10\mathop{\mathrm{f}\/}\nolimits\!\left(z\right)=\left(\tfrac{1}{2}-\mathop{S\/}\nolimits\!\left(z\right)\right)\mathop{\cos\/}\nolimits\!\left(\tfrac{1}{2}\pi z^{2}\right)-\left(\tfrac{1}{2}-\mathop{C\/}\nolimits\!\left(z\right)\right)\mathop{\sin\/}\nolimits\!\left(\tfrac{1}{2}\pi z^{2}\right),
7.2.11\mathop{\mathrm{g}\/}\nolimits\!\left(z\right)=\left(\tfrac{1}{2}-\mathop{C\/}\nolimits\!\left(z\right)\right)\mathop{\cos\/}\nolimits\!\left(\tfrac{1}{2}\pi z^{2}\right)+\left(\tfrac{1}{2}-\mathop{S\/}\nolimits\!\left(z\right)\right)\mathop{\sin\/}\nolimits\!\left(\tfrac{1}{2}\pi z^{2}\right).

§7.2(v) Goodwin–Staton Integral

7.2.12\mathop{G\/}\nolimits\!\left(z\right)=\int _{0}^{\infty}\frac{e^{{-t^{2}}}}{t+z}dt,|\mathop{\mathrm{ph}\/}\nolimits z|<\pi.