Write code in c++ for calculating square root

Here is an example of a function in C++ that calculates the square root of a given number using the Newton-Raphson method:

#include <cmath>

double square_root(double x) {

    double root = x;

    double precision = 0.00001;

    while (fabs(root * root - x) > precision) {

        root = (root + x / root) / 2;

    }

    return root;

}

Note: The above code uses the fabs function from the cmath library which returns the absolute value of a float or double. This function is used to compare the square of the approximation to the original number and check if the approximation is accurate enough.

OR

#include <cmath>

#include <iostream>

int main() {

    double num;

    std::cout << "Enter a number: ";

    std::cin >> num;

    double sqrt_num = sqrt(num);

    std::cout << "The square root of " << num << " is " << sqrt_num << std::endl;

    return 0;

}

This code takes a user input and uses the sqrt() function from the cmath library to calculate the square root of the input. The result is then printed to the console.

Note: The sqrt() function in cmath library is for floating-point numbers. If you want to calculate the square root for integers, you can use the sqrt() function from math.h or you can use the newton-raphson method to calculate square root of any number.