Segmentation Fault in Function Call

So I've got my program to the point where it compiles, but upon calling up the other functions the program drops with a Segmentation Fault(core dumped) error. Everything works until then. I'll add the entire code in case the setup is wrong (possible as I don't particularly understand pointers or passing values and such)

#include <cmath>
#include <iostream>
using namespace std;

void discrim0(float a, float b, float c, float * root1, float * root2);
void discrimmore(float a, float b, float c, float * root1, float * root2);
void discrimless(float a, float b, float c, float * real, float * sqrtim);

int main()
{

 float discrim;
 float a;
 float b;
 float c;
 float * root1=0;
 float * root2=0;
 float * real=0;
 float * sqrtim=0;
 char cAgain;

 cout << "Welcome to the quadratic roots calculator." <<endl;

 do
 {
  do
  {

   cout << "Please enter the three coefficient values of the" <<endl;
   cout << "quadratic equation. The coefficient of x^2 must not"<<endl;
   cout << "be 0." <<endl;

   cin >> a >> b >> c;

   if(a==0)
   {
    cout << "The value you entered for the coefficient of x^2"<<endl;
    cout << "is not valid(0). Please enter a proper value."<<endl;
   }
  }while(a==0);


  discrim=(b*b)-4*a*c;

  if(discrim<0)
   {
    cout << "Your equation has two imaginary roots."<<endl;
    //error occurs here
    discrimless(a,b,c, real, sqrtim);
    cout << *real << " + " << *sqrtim << "i" << endl;
    cout << "and" << endl;
    cout << *real << " - " << *sqrtim << "i" << endl;
   }

   if(discrim==0)
   {
    cout << "Your equation two roots of the same value."<<endl;
    //error occurs here
    discrim0(a,b,c, root1, root2);
    cout << *root1 << " and " << *root2 << endl;
   }

   if(discrim>=0)
   {
    cout << "Your equation has two real roots, which are: "<<endl;
    //error occurs here
    discrimmore(a,b,c, root1, root2);
    cout << *root1 << " and " << *root2;
   }

   cout << "Would you like to run another calculation? Y/y/N/n"<<endl;
   cin >> cAgain;

  }while(cAgain=='Y'||cAgain=='y');

  return 0;
 }

 void discrim0(float a, float b, float c, float * root1, float * root2)
 {
  *root1= ((-b + sqrt((b*b)-4*a*c))/2*a);

  *root2= ((-b - sqrt((b*b)-4*a*c))/2*a);
 }

 void discrimless(float a, float b, float c, float * real, float * sqrtim)
 {
  *real= (-b)/(2*a);
  *sqrtim= (sqrt(-(b*b-4*a*c)))/(2*a);

 }

 void discrimmore(float a, float b, float c, float *  root1, float * root2)
 {
  *root1= ((-b + sqrt((b*b)-4*a*c))/2*a);

  *root2=((-b - sqrt((b*b)-4*a*c))/2*a);
 }

I marked in the code where it happens. Essentially it will tell you the number of roots and then crash. I understand the general idea of seg fault that I am trying to access memory I don't have or something to that effect, but I don't really know why it is occurring. Also please keep in mind that I don't really understand technical speak too well. Thanks.