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The header <math.h> declares mathematical
functions and macros.
The macros EDOM and ERANGE (found in errno.h) are non-integral
constants that are used to signal domain and range errors for the
functions; HUGH_VAL is a positive double
value. A domain error occurs if an argument is
outside the domain over which the function is defined. On a
domain error, errno is set to EDOM; the
return value is implementation-dependent. A range
error occurs if the result of the function cannot be
represented as a double. If the result overflows,
the function returns HUGH_VAL with the right sign, and
errno is set to ERANGE. If the result
underflows, the function returns zero; whether errno is
set to ERANGE is implementation-defined.
In the following table, x and y are of
type double, n is an int, and
all functions return double. Angles for
trigonometric functions are expressed in radians.
sin(x) |
sine of x | |||
cos(x) |
cosine of x | |||
tan(x) |
tangent of x | |||
asin(x) |
sin-1(x) in range [-pi / 2, pi / 2], x in set [-1, 1] | |||
acos(x) |
cos-1(x) in range [0, pi], x in set [-1, 1] | |||
atan(x) |
tan-1(x) in range [-pi / 2, pi / 2] | |||
atan2(y,x) |
tan-1(y / x) in range [-pi, pi] | |||
sinh(x) |
hyperbolic sine of x | |||
cosh(x) |
hyperbolic cosine of x | |||
tanh(x) |
hyperbolic tangent of x | |||
exp(x) |
exponential function ex | |||
log(x) |
natural logarithm ln(x), x > 0 | |||
log10(x) |
base 10 logarithm log10(x), x > 0 | |||
pow(x,y) |
x y. A domain error occurs if
x=0 and y <= 0, or if x<0 and
y is not an integer |
|||
sqrt(x) |
Square root of x, x >= 0 | |||
ceil(x) |
smallest integer not less than x, as a
double |
|||
floor(x) |
largest integer not greater than x, as a
double |
|||
fabs(x) |
absolute value |x| | |||
ldexp(x,n) |
x·2n | |||
frexp(x, int *exp) |
splits x into a normalised fraction in the
interval [1/2, 1], which is returned, and a power of 2, which
is stored in *exp. If x is
zero, both parts of the result are zero.
|
|||
modf(x, double *ip) |
splits x into integral and fractional parts, each
with the same sign as x. It stores the
integral part in *ip, and returns the fractional
part
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fmod(x,y) |
floating-point remainder of x/y, with the same
sign as x. If y is zero, the
result is implementation-defined.
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Last modified: Mon Mar 27 13:34:02 2000
