## C Program To Evaluate A Polynomial

Learn How To Write a Code To Evaluate A Polynomial in C Programming Language. For Evaluation of a Polynomial, we first fetch the value of Co – Efficient and store them in the Array. This program is intimidating but is actually very simple if you try a little harder to understand it.

#### What is Polynomial?

A Polynomial is an expression or a mathematical equation which contains variables and constants (also known as Co – Efficients). The different terms in the expression includes the operations of Addition, Non – Negative Integer Exponent, Subtraction and Multiplication. A polynomial is nothing but an algebraic expression. It is also famously known as arithmetic expression.

**Must Read: C Program To Evaluate a Postfix Expression**

#### Method 1: C Program To Evaluate a Polynomial using Function

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 | #include<stdio.h> #include<math.h> int evaluate_polynomial(int arr[], int limit, int x) { int sum = 0, count; for(count = limit; count >= 0; count--) { sum = sum + arr[count]*pow(x, count); } return sum; } int main() { int array[30], degree, x_val, count, result; printf("\nEnter the Degree of Polynomial:\t"); scanf("%d", °ree); printf("\nEnter the Co - Efficients:\n"); for(count = degree; count >= 0; count--) { printf("\nCo - Efficient of A[%d]: \t", degree); scanf("%d", &array[count]); } printf("\nThe Polynomial:\n\n"); for(count = degree; count >= 0; count--) { if(array[count] != 0) { printf("%dx^%d + ", array[count], count); } } printf("%d", array[count]); printf("\n\nEnter the Value of X:\t"); scanf("%d", &x_val); result = evaluate_polynomial(array, degree, x_val); printf("\nEvaluation of Polynomial:\t%d\n", result); return 0; } |

#### Method 2: C Program To Evaluate a Polynomial without Function

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 | #include<stdio.h> #include<math.h> int main() { int array[30], degree, x_val, count, sum = 0; printf("\nEnter the Degree of Polynomial:\t"); scanf("%d", °ree); printf("\nEnter the Co - Efficients:\n"); for(count = degree; count >= 0; count--) { printf("\nCo - Efficient of A[%d]: \t", degree); scanf("%d", &array[count]); } printf("\nThe Polynomial:\n\n"); for(count = degree; count >= 0; count--) { if(array[count] != 0) { printf("%dx^%d + ", array[count], count); } } printf("%d", array[count]); printf("\n\nEnter the Value of X:\t"); scanf("%d", &x_val); for(count = degree; count >= 0; count--) { sum = sum + array[count]*pow(x_val, count); } printf("\nEvaluation of Polynomial:\t%d\n", sum); return 0; } |

#### Method 3: C Program To Evaluate a Polynomial using Horner’s Method

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | #include<stdio.h> int evaluate_polynomial(int array[], int limit, int degree) { int value = array[0]; for(int count = 1; count < limit; count++) value = (value * degree) + array[count]; return value; } int main() { int degree = 3; int array[] = {3, 4, 2, 1, 2}; int limit = sizeof(array)/sizeof(array[0]); printf("\nValue of Polynomial:\t%d\n", evaluate_polynomial(array, limit, degree)); return 0; } |

#### Output

If you have any compilation error or doubts in this C Program For Evaluation of Polynomial, let us know about it in the Comment Section below.

The Horner’s method for evaluating a polynomial seems to take Hard Coded values. Will the user defined values work in Horner method like they work in the above two C Programs?

Yes! It will definitely work. The Horner’s method to evaluate a polynomial here takes a hard coded array. You can take input for the array from the User. I think it should work.

So many methods to solve and evaluate a polynomial expression in c programming helped to clear how and when to use functions. Also it helped to analyze how to convert functions into main programs.

I am glad that you liked it. The main reason behind posting 2 different ways of writing how to calculate and evaluate a polynomial in c is to make the programmers understand the minute difference between for and while loops as well as functional approach.

This C Program to evaluate an arithmetic expression is just to good. Thanks.

I implement the polynomial program and i extract the order and coefficients of the given polynomial . I enter x value to that polynomial but it is not giving the correct value.