Write the definition of a function named quadratic that receives three double parameters a, b, c. if the value of a is 0 then the function prints the message "no solution for a=0" and returns. if the value of "b squared" – 4ac is negative, then the code prints out the message "no real solutions" and returns. otherwise the function prints out the largest solution to the quadratic equation.

#include <iostream>

#include <cmath>

using namespace std;

//initialize function quadratic

void quadratic(double, double, double);

int main() {

   //declare double variables a, b and c

   double a,b,c;

   //take input from user

   cin>>a>>b>>c;

   //call function quadratic

   quadratic(a,b,c);

return 0;

}

void quadratic(double a, double b, double  c){

   double root,n;

   //check if variable a is equal to zero

   if(a==0){

       cout<<"no solution for a=0"<<endl;

       return;

   }

   //check if b squared - 4ac is less than zero

   else

   if(((b*b)-(4*a*c))<0){

       cout<<"no real solutions"<<endl;

       return;

   }

   //print the largest root if the above conditions are not satisfied

   else{

       n=((b*b)-(4*a*c));

       root=(-b + sqrt(n)) / (2*a);

       cout<<"Largest root is:"<<root<<endl;

   }

   return ;

}

Explanation:

Read three double variables a, b and c from the user and pass it to the function quadratic. Check if the value of variable a is equal to zero. If true, print "no solution for a=0". If this condition is false, check if b squared - 4ac is less than zero. If true, print "no real solutions". If this condition is also false, calculate the largest solution using the following formula:

largest root = (-b + square root of (b squared - 4ac)) / (2*a)

Input 1:

2 5 3

Output 2:

Largest root is:-1

Input 2:

5 6 1

Output 2:

Largest root is:-0.2