我得到的問題是，當我插入公式1x^2 + 3x +4時，我得到x = -Infinity和x =無窮大，而不是x = 1和x = -4。

繼承人我的代碼：

第1類：

public class quadratictest

{

public static void main(String args[])

{

DecimalFormat df = new DecimalFormat("#.###");

System.out.println("--------------------------------------------------");

System.out.println(" ~Quadratic Formula~");

System.out.println("--------------------------------------------------");

System.out.println("in a polynomial, there are 3 important numbers used");

System.out.println("to figure out x. they are a, b, and c, shown below.\n");

System.out.println("\t\t1x^2 +3x +4");

System.out.println("\t\t^ ^ ^");

System.out.println("\t\ta b c");

Scanner input = new Scanner(System.in);

System.out.print("\nPlease type a, b, and c here[a b c]: ");

int a = input.nextInt();

int b = input.nextInt();

int c = input.nextInt();

mathey quad = new quadsong(a,b,c);

System.out.println("------------");

System.out.println(quad.solveb());

System.out.println(quad.solvea());

//System.out.println("x =" +df.format(quad.solvea()));

//System.out.println("x =" +df.format(quad.solveb()));

System.out.println("------------");

}

}

2類：

import java.util.*;

import java.io.*;

import java.text.DecimalFormat;

/**

* Write a description of class quadsong here.

*

* @author (your name)

* @version (a version number or a date)

*/

public class mathey

{

int a;int b;int c;

double solution1;

double solution2;

public mathey(int aN, int bN, int cN)

{

int a = aN;

int b = bN;

int c = cN;

solvea();

solveb();

}

public double solvea()

{

solution1 = ((b*-1) + Math.sqrt((b^2)-(4*a*c)))/(a+a);

if (solution1 == Math.floor(solution1))

{

return solution1;

}

else

{

return 0;

}

}

public double solveb()

{

solution2 = ((b*-1) - Math.sqrt((b^2)-(4*a*c)))/(2*a);

if (solution2 == Math.floor(solution2))

{

return solution2;

}

else

{

return 0;

}

}

}

我的繼承人輸出：

--------------------------------------------------

~Quadratic Formula~

--------------------------------------------------

in a polynomial, there are 3 important numbers used

to figure out x. they are a, b, and c, shown below.

1x^2 +3x +4

^ ^^

a b c

Please type a, b, and c here[a b c]: 1 3 4

------------

x =Infinity

x =-Infinity

------------

請告訴我去錯了嗎？提前致謝！ P.S對不起，代碼格式，idk爲什麼它不工作就像我想在這裏哈哈