## Mathematical Constants

The library ensures that the standard BSD mathematical constants are defined. For reference here is a list of the constants.

`M_E`
  The base of exponentials, e
`M_LOG2E`
  The base-2 logarithm of e, \log_2 (e)
`M_LOG10E`
  The base-10 logarithm of e, \log_10 (e)
`M_SQRT2`
  The square root of two, \sqrt 2
`M_SQRT1_2`
  The square root of one-half, \sqrt{1/2}
`M_SQRT3`
  The square root of three, \sqrt 3
`M_PI`
  The constant pi, \pi
`M_PI_2`
  Pi divided by two, \pi/2
`M_PI_4`
  Pi divided by four, \pi/4
`M_SQRTPI`
  The square root of pi, \sqrt\pi
`M_2_SQRTPI`
  Two divided by the square root of pi, 2/\sqrt\pi
`M_1_PI`
  The reciprocal of pi, 1/\pi
`M_2_PI`
  Twice the reciprocal of pi, 2/\pi
`M_LN10`
  The natural logarithm of ten, \ln(10)
`M_LN2`
  The natural logarithm of two, \ln(2)
`M_LNPI`
  The natural logarithm of pi, \ln(\pi)
`M_EULER`
  Euler's constant, \gamma