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# std::cbrt

From cppreference.com
< cpp‎ | numeric‎ | math

Defined in header `<cmath>` |  |
float cbrt( float arg ); | (1) | (since C++11)
double cbrt( double arg ); | (2) | (since C++11)
long double cbrt( long double arg ); | (3) | (since C++11)
double cbrt( Integral arg ); | (4) | (since C++11)

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).

### [edit] Parameters

arg | - | value of a floating-point or Integral type

### [edit] 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.

### [edit] 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.

### [edit] 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.

### [edit] Example

Run this code

    #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

### [edit] See also

pow | raises a number to the given power (xy) (function) [edit]
sqrt | computes square root (√x) (function) [edit]
hypot (C++11) | computes square root of the sum of the squares of two given numbers (√x2 +y2 ) (function) [edit]
C documentation for cbrt

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