bc: Math Library Functions

 
 5.1 Math Library Functions
 ==========================
 
 If 'bc' is invoked with the '-l' option, a math library is preloaded and
 the default SCALE is set to 20.  The math functions will calculate their
 results to the scale set at the time of their call.  The math library
 defines the following functions:
 
 's (X)'
      The sine of X, X is in radians.
 
 'c (X)'
      The cosine of X, X is in radians.
 
 'a (X)'
      The arctangent of X, arctangent returns radians.
 
 'l (X)'
      The natural logarithm of X.
 
 'e (X)'
      The exponential function of raising E to the value X.
 
 'j (N, X)'
      The Bessel function of integer order N of X.