Answer:
In C
#include <stdio.h>
#include<math.h>
void myfunc(double *a, double *b, double *c) {
 double x1, x2;
 x1 = (-(*b) + sqrt((*b)*(*b)- 4*(*a)*(*c)))/(2*(*a));
 x2 = (-(*b) - sqrt((*b)*(*b) - 4*(*a)*(*c)))/(2*(*a));
 printf("x1 = %f\n",x1);
 printf("x2 = %f\n",x2);}
int main () {
 double a,b,c;
 printf("a: "); scanf("%lf", &a);
 printf("b: "); scanf("%lf", &b);
 printf("c: "); scanf("%lf", &c);
 myfunc(&a, &b, &c);
 return 0;}
Explanation:
#include <stdio.h>
#include<math.h> Â --- This represents step 1
Step 2 begins here
This gets the values of a, b and c from main by reference
void myfunc(double *a, double *b, double *c) {
This declares x1 and x2
 double x1, x2;
Calculate x1
 x1 = (-(*b) + sqrt((*b)*(*b)- 4*(*a)*(*c)))/(2*(*a));
Calculate x2
 x2 = (-(*b) - sqrt((*b)*(*b) - 4*(*a)*(*c)))/(2*(*a));
Print x1
 printf("x1 = %f\n",x1);
Print x2
 printf("x2 = %f\n",x2);}
Step 3 begins here
int main () {
Declare a, b and c as double
 double a,b,c;
Get input for a, b and c
 printf("a: "); scanf("%lf", &a);
 printf("b: "); scanf("%lf", &b);
 printf("c: "); scanf("%lf", &c);
Call the function to calculate and print x1 and x2
 myfunc(&a, &b, &c);
 return 0;}