## Arithmetic Functions

Nine of the built-in functions can be classified as arithmetic functions. Most of them take a numeric argument and return a numeric value. Table 9.1 summarizes these arithmetic functions.

Awk Function | Description |

cos(x) | Returns cosine of x
(x is in radians). |

exp(x) | Returns e to the power
x. |

int(x) | Returns truncated value of
x. |

log(x) | Returns natural logarithm (base-e)
of x. |

sin(x) | Returns sine of x
(x is in radians). |

sqrt(x) | Returns square root of x. |

atan2(y,x) | Returns arctangent of
y/x in the range -π to
π. |

rand( ) | Returns pseudo-random number r,
where 0 <= r < 1. |

srand(x) | Establishes new seed for |

### Trigonometric Functions

The trigonometric functions **cos(
)** and **sin( )** work the same
way, taking a single argument that is the size of an angle in radians
and returning the cosine or sine for that angle. (To convert from
degrees to radians, multiply the number by π/180.) The trigonometric
function **atan2( )** takes two arguments
and returns the arctangent of their quotient. The expression

atan2(0, -1)

produces π.

The function **exp( )**
uses the natural exponential, which is also known as
base-*e* exponentiation. The expression

exp(1)

returns the natural number 2.71828, the base of the
natural logarithms, referred to as *e*. Thus,
**exp**(*x*) is
*e* to the *x*-th power.

The **log( )** function
gives the inverse of the **exp( )**
function, the natural logarithm of *x*. The
**sqrt( )** function takes ...

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