In this C++ tutorial, you will learn how to compute cube root of a given number using cbrt() function of cmath, with syntax and examples.

C++ cbrt()

C++ cbrt() computes cube root of given number (argument).

Syntax

The syntax of C++ cbrt() is

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cbrt(x)

where

ParameterDescription
xA double, float, long double, or any integral type value.

Returns

The return value depends on the type of value passed for parameter x.

The return value of cbrt(x) is

  • double if x is double or integral type.
  • float if x is float.
  • long double if x is long double.

The synopsis of cbrt() function is

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double cbrt(double x);
float cbrt(float x);
long double cbrt(long double x);
double cbrt(T x); // for integral type argument values

cbrt() is a function of cmath library. Include cmath library at the start of program, if using cbrt() function.

Example

In this example, we read a value from user into variable x, and find its cube root using cbrt() function.

C++ Program

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#include <iostream>
#include<cmath>
using namespace std;

int main() {
    double x;
    cout << "Enter a number : ";
    cin >> x;
    
    double result = cbrt(x);
    cout << "cbrt(" << x << ") : " << result << endl;
}

Output

Enter a number : 27
cbrt(27) : 3
Program ended with exit code: 0
Enter a number : -27
cbrt(-27) : -3
Program ended with exit code: 0

Conclusion

In this C++ Tutorial, we learned the syntax of C++ cbrt(), and how to use this function to find the cube root of given number, with the help of examples.