= Math:  cbrt, sqrt, pow, pow10, hypot, exp, expm1, log, log10, log1p, cos, cosh, sin, sinh, tan, tanh,  acos,  asin,  acosh, asinh, atan, atanh, atan2, lgamma, erf, erfc, j0, j1, y0, y1, jn, yn: elementary functions of applied mathematics     include "math.m";    math := load Math Math->PATH;        cbrt, sqrt: fn(x: real): real;    pow: fn(x, y: real): real;    pow10: fn(p: int): real;    hypot: fn(x, y: real): real;    exp, expm1, log, log10, log1p: fn(x: real): real;        cos, cosh, sin, sinh, tan, tanh: fn(x: real): real;    acos, asin, acosh, asinh, atan, atanh: fn(x: real): real;    atan2: fn(y, x: real) of real;        lgamma: fn(x: real): (int,real);    erf, erfc: fn(x: real): real;    j0, j1, y0, y1: fn(x: real): real;    jn, yn: fn(n: int, x: real): real; These routines implement the basic  elementary  functions  ofapplied mathematics. Sqrt(x) computes the square root of x, cbrt(x) the cube root.Pow(x,y) computes x raised to the exponent y; pow10 raises 10to the integer power n.  Hypot(x,y) computes sqrt(x*x+y*y). Exp(x) returns the exponential function of x, and expm1(x) isexp(x)-1. Log(x) returns the natural logarithm  of  x,  while  log10(x)returns  the logarithm base 10 and log1p(x) returns the loga‐rithm of 1+x. The trigonometric functions use radians.  The ranges  of  theinverse  functions  are:  acos  in [0,π]; asin in [-π/2,π/2];atan in [-π/2,π/2]; and atan2(y,x) = arctan(y/x) in [-π,π]; The gamma function is implemented by lgamma(x); the tuple  itreturns,  say  (s,lg),  encodes  the gamma function by Γ(x) =s*exp(lg). The hyperbolic trigonometric functions sinh  etc.  behave  asexpected.  Erf is the error function and erfc(x) is 1-erf(x). The  Bessel functions are computed by j0, j1, jn, y0, y1, andyn. == source/libinterp/math.c == see ALSOmath-intro(2)