atan2(Y,X)  Returns the arctangent of Y/X.

cos(EXPR)
cos EXPR    Returns the cosine of EXPR in radians. If EXPR is omitted, takes cosine of $_.

exp(EXPR)
exp EXPR    Returns e to the power of EXPR. If EXPR is omitted, gives exp($_).

int(EXPR)
int EXPR    Returns the integer portion of EXPR. If EXPR is omitted, uses $_.

log(EXPR)
log EXPR    Returns logarithm (base e) of EXPR. If EXPR is omitted, returns log of $_.

rand(EXPR)
rand EXPR
rand        Returns a random fractional number between 0 and the value of EXPR. 
            If EXPR is omitted, returns a value between 0 and 1.

sin(EXPR)
sin EXPR    Returns the sine of EXPR in radians. If EXPR is omitted, returns sine of $_.

sqrt(EXPR)
sqrt EXPR   Return the square root of EXPR. If EXPR is omitted, returns square root of $_.

srand(EXPR)
srand EXPR  Sets the random number seed for the rand operator. If EXPR is omitted, does srand(time).