sqrt

C:

#include <stdio.h>

#define Zero 1e-6

float mysqrt(int number) {
	
	float guess = 1.0f;
	float quotient = number/guess;
	float average = (guess + quotient)/2.0;
	
	do {
		guess = average;
		quotient = number/guess;
		average = (guess + quotient)/2.0;
		printf("%f\n", guess);
		
	}while (guess*guess - number >= Zero);
	
	return guess;
}

int main() {
	int number;
	scanf("%d", &number);
	printf(" your sqrt is %f", mysqrt(number));
	return 0;
}

scheme:

(define (improve guess x)
        (average guess (/ x guess)))
        
(define (goodenough guess x)
        (< (abs (- (square guess) x) 0.00001))

(define (sqrt-iter guess x)
        (if (goodenough guess x)
                guess
                (sqrt-iter (improve guess x)
                x)))
                
(define (mymsqrt x)
        (sqrt-iter 1.0 x))           
        
(mysqrt 9)