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Several ways can find or calculate square roots in C++ programming without using sqrt function. However, to get the answer, several iterations may be required for some large numbers which might appear inconveniencing. 

Methods

  1. Log method
  2. Power algorithm

Illustrations

All the methods are explained with illustratoins below.

 

Log method

Below is one simple log method that can be used:

// C++ program to show finding 

// square root of a number using log2() 

#include<bits/stdc++.h> 

double squareRoot(double n) 

{ 

    return pow(2, 0.5*log2(n)); 

} 

int main(void) 

{ 

    double n = 12; 

    printf("%lf ", squareRoot(n)); 

    return 0; 

} 

 

The declarations of all variables must be made which means the programmer has to specify the value of log and the value of n whose square root needs to be found. 

 

Power algorithm

Below is the power algorithm. The algorithm raises the value of x ^y i.e. x raised to power of y. The power syntax is:

#include <math.h>

double pow(double x, double y);

 

Another one

Example of how to find square root using double/ power function is shown below:

x = int(input())

 import math 

print(pow(x, 0.5))

 or

print(x**0.5)

Note: if the value of x above is negative, the return value is NaN

Hope this helps.

100 points
7 2