Program to find the roots of a quadratic equation Using C

# include <stdio.h>
# include <conio.h>
# include <math.h>

void main()
{
float a, b, c, d, real, imag, r1, r2, n ;
int k ;
clrscr() ;
printf("Enter the values of A, B & C : ") ;
scanf("%f %f %f", &a, &b, &c) ;
if(a != 0)
{
d = b * b - 4 * a * c ;
if(d < 0)
k = 1 ;
if(d == 0)
k = 2 ;
if(d > 0)
k = 3;
switch(k)
{
case 1 :
printf("\nRoots are imaginary\n") ;
real = - b / (2 * a) ;
d = - d ;
n = pow((double) d, (double) 0.5) ;
imag = n / (2 * a) ;
printf("\nr1 = %7.2f + j%7.2f", real, imag) ;
printf("\nr2 = %7.2f - j%7.2f", real, imag) ;
break ;
case 2 :
printf("\nRoots are real and equal\n") ;
r1 = - b / (2 * a) ;
printf("\nr1 = r2 = %7.2f", r1) ;
break ;
case 3 :
printf("\nRoots are real and unequal\n") ;
r1 = (- b + sqrt((double) d)) / (2 * a) ;
r2 = (- b - sqrt((double) d)) / (2 * a) ;
printf("\nr1 = %7.2f",r1) ;
printf("\nr2 = %7.2f",r2) ;
break ;
}
}
else
printf("\nEquation is linear") ;
getch() ;
}


~~~~~~~
Enter the values of A, B & C : 0.0 4.0 7.0
Equation is linear
RUN 2 :
~~~~~~~
Enter the values of A, B & C : 1.0 2.0 7.0
Roots are imaginary
r1 = -1.00 + j 2.45
r2 = -1.00 - j 2.45
RUN 3 :
~~~~~~~
Enter the values of A, B & C : 1.0 2.0 1.0
Roots are real and equal
r1 = r2 = -1.00
RUN 4 :
~~~~~~~
Enter the Values of A, B & C : 2.0 7.0 1.0
Roots are real and unequal
r1 = -0.15
r2 = -3.35