std::cbrt, std::cbrtf, std::cbrtl
Defined in header <cmath> | ||
---|---|---|
float cbrt ( float arg ); float cbrtf( float arg ); | (1) | (since C++11) |
double cbrt ( double arg ); | (2) | (since C++11) |
long double cbrt ( long double arg ); long double cbrtl( long double arg ); | (3) | (since C++11) |
double cbrt ( IntegralType arg ); | (4) | (since C++11) |
1-3) Computes the cubic root of
arg
.
4) A set of overloads or a function template accepting an argument of any integral type. Equivalent to 2) (the argument is cast to
double
).Parameters
arg | - | value of a floating-point or Integral type |
Return value
If no errors occur, the cubic root of arg
(3√arg), is returned.
If a range error occurs due to underflow, the correct result (after rounding) is returned.
Error handling
Errors are reported as specified in math_errhandling
.
If the implementation supports IEEE floating-point arithmetic (IEC 60559),
- if the argument is ±0 or ±∞, it is returned, unchanged
- if the argument is NaN, NaN is returned.
Notes
std::cbrt(arg)
is not equivalent to std::pow(arg, 1.0/3)
because std::pow
cannot raise a negative base to a fractional exponent.
Example
#include <iostream> #include <cmath> int main() { // normal use std::cout << "cbrt(729) = " << std::cbrt(729) << '\n' << "cbrt(-0.125) = " << std::cbrt(-0.125) << '\n'; // special values std::cout << "cbrt(-0) = " << std::cbrt(-0.0) << '\n' << "cbrt(+inf) = " << std::cbrt(INFINITY) << '\n'; }
Output:
cbrt(729) = 9 cbrt(-0.125) = -0.5 cbrt(-0) = -0 cbrt(+inf) = inf
See also
(C++11)(C++11) | raises a number to the given power (xy) (function) |
(C++11)(C++11) | computes square root (√x) (function) |
(C++11)(C++11)(C++11) | computes square root of the sum of the squares of two given numbers (√x2 +y2 ) (function) |
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