Answer to Question #197831 in C++ for adil ramzan

Question

Write a C++ function that evaluates polynomials an a n x n + a n-1 x n-1 , … , a 2 x 2 ,a 1 x 1 , a 0

x 0 . It should take following inputs:

Value of x.

Highest power n.

Coefficients in descending order a n , a n-1 , … , a 2 , a 1 , a 0 (coefficients will ne

n+1)

For instance, if x=4 , n=3 & coefficients are [2,3,1,2], then output should be 182 which is

obtained by evaluating the polynomial 2 * 4 3 + 3 * 4 2 + 1 * 4 1 + 2 * 4 0

Function Prototype: double evaluatePolynomial();

without using array in c++

Answer 1

#include <iostream>
#include <cmath>

using namespace std;

double evaluatePolynomial(double x, int n, double coeff[])
{
    double result = 0;
    for (int i = n; i >= 0; i--) {
        result += coeff[n-i] * pow(x, i);
    }
    return result;
}

int main() 
{
    double x = 4;
    int n = 3;
    double coeff[4] {2, 3, 1, 2};
    
    cout << evaluatePolynomial(x, n, coeff);
    
    return 0;
}