These mathematical functions allow integers as well as floating-point numbers as arguments.
sin
arg ¶cos
arg ¶tan
arg ¶These are the basic trigonometric functions, with argument arg measured in radians.
asin
arg ¶The value of (asin arg)
is a number between
−pi/2
and
pi/2
(inclusive) whose sine is arg. If arg is out of range
(outside [−1, 1]), asin
returns a NaN.
acos
arg ¶The value of (acos arg)
is a number between 0 and
pi
(inclusive) whose cosine is arg. If arg is out of range
(outside [−1, 1]), acos
returns a NaN.
atan
y &optional x ¶The value of (atan y)
is a number between
−pi/2
and
pi/2
(exclusive) whose tangent is y. If the optional second
argument x is given, the value of (atan y x)
is the
angle in radians between the vector [x, y]
and the
X
axis.
exp
arg ¶This is the exponential function; it returns e to the power arg.
log
arg &optional base ¶This function returns the logarithm of arg, with base
base. If you don’t specify base, the natural base
e is used. If arg or base is negative, log
returns a NaN.
expt
x y ¶This function returns x raised to power y. If both
arguments are integers and y is nonnegative, the result is an
integer; in this case, overflow signals an error, so watch out.
If x is a finite negative number and y is a finite
non-integer, expt
returns a NaN.
sqrt
arg ¶This returns the square root of arg. If arg is finite
and less than zero, sqrt
returns a NaN.
In addition, Emacs defines the following common mathematical constants:
The mathematical constant e (2.71828…).
The mathematical constant pi (3.14159…).