Complete Program

Translating the polynomial

7x³- 3x² + 4x - 12

into Java is easy. The term x³ means x times itself three times, so that is what the Java statement does.

The integers in the expression (such as the 7) will automatically be converted to double, so the entire calculation will be done with double precision.

The next statement writes out the answer. The + operator concatenates the strings. Remember that doubles are converted to strings automatically when you use + between a double and a string.

import java.util.Scanner;

public class EvalPoly
{
  public static void main (String[] args )  
  {
    Scanner scan = new Scanner ( System.in );

    double x;                      // a value to use with the polynomial
    double result;                 // result of evaluating the polynomial at x
    String response = "y";         // "y" or "n"

    while ( response.equals( "y" ) )    
    {
       // Get a value for x.
       System.out.println("Enter a value for x:")  ;
       x = scan.nextDouble();

       // Evaluate the polynomial.
       result =7*x*x*x - 3*x*x + 4*x - 12;

       // Print out the result.
       System.out.println("The value of the polynomial at x = " +
           x + " is: " + result + "\n"  ) ;

       // Ask the user if the program should continue.
       System.out.println("continue (y or n)?");
       response = scan.next();      
    }

  }
}

Answer:

Complete Program

QUESTION 21: