A number is square root of if

Most programming languages have an in-built sqrt function. But it can be easily calculated using binary search.

float sqrt(n) {
    low = 0.0;
    high = (float)n+1;
    while ((high-low) > 0.00001) {
        mid = (low+high) / 2;
        if (mid*mid < n) {
            low = mid;
        }
        else {
            high = mid;
        }
    }
    return low;
}

Note that we do not check high - low == some_value This is because we never equate float values. Instead, we use a small epsilon value and use that as an error tolerance.

Newton Raphson Method:

#include <stdio.h>
// Function to get absolute value of the number given by user.
float absolute(float num)
{
    if(num < 0){
        num = -num;
    }
    return num;
}
// Function to calculate square root of the number using Newton-Raphson method
float square_root(int x)
{
    const float difference = 0.00001;
    float guess = 1.0;
    while(absolute(guess * guess - x) >= difference){
        guess = (x/guess + guess)/2.0;
    }
    return guess;
}

int main()
{
    int number;
    float root;
    printf("Enter a number: ");
    scanf("%i", &number);
    root = square_root(number);
    printf("The square root of %i is: %f", number, root);
    return 0;
}