3.11 Approximation Techniques4 Elementary Functions

§3.12 Mathematical Constants

The fundamental constant

3.12.1 \pi=3.14159\; 26535\; 89793\; 23846\;\ldots

can be defined analytically in numerous ways, for example,

3.12.2 \pi=4\int _{0}^{1}\frac{dt}{1+t^{2}}.

Other constants that appear in the DLMF include the base e of natural logarithms

3.12.3 e=2.71828\; 18284\; 59045\; 23536\;\ldots\,,

see §4.2(ii), and Euler’s constant \EulerConstant

3.12.4 \EulerConstant=0.57721\; 56649\; 0 1532\; 86060\;\ldots,

see §5.2(ii).

For access to online high-precision numerical values of mathematical constants see Sloane (2003). For historical and other information see Finch (2003).