Wrong answer.

[Maynza]

Wrong answer.

I know this is simple, but I am teaching myself and i am trying to figure out why I am getting the wrong answer.

I think it is probably my order of operations.

#include <iostream>
#include <cmath>

using namespace std;

int main()
{
  cout<<"The Quadratic Formula is represented as..."<<endl;
  cout<<"-b+sqrt(b^2-4ac)/2a \n& \n-b-sqrt(b^2-4ac)/2a"<<endl;
  cout<<"Enter the value of your polynomials."<<endl;
  double a, b, c, x1, x2, q;
  cout<<"A=";
  cin>>a;
  cout<<"\nB=";
  cin>>b;
  cout<<"\nC=";
  cin>>c;
  x1 = (-b+sqrt((b*b)-4*a*c))/2*a;
  cout<<"X="<<x1;
  cin>>q;
  return 0;
}

 

[arul]

I'd try to put a parentheses there, since the numerator part of the expression "(-b+sqrt((b*b)-4*a*c))" is divided by 2, then multiplied by A.

 x1 = (-b+sqrt((b*b)-4*a*c))/[B][COLOR="Red"]([/COLOR][/B]2*a[B][COLOR="#ff0000"])[/COLOR][/B];

 

[Maynza]

it is still giving me -1.#IND

I'm using 1,3,4 as A,B,C and I am thinking i should be getting -4

 

[arul]

Those numbers sounds like an error to me, because they will give you a negative argument to the sqrt, which will result in mathematical error.

3^2 - 4 * 1 * 4  = 9 - 16 = -7

You can't compute a square root of the negative number in the scope of real numbers. ( you would need to work with the complex numbers )

 

[Maynza]

ahh ok. I was too lazy to make my own polynomial and the one i was using was wrong

 

[Maynza]

nvm problem solved.