Quadratic equation

[ginevralupin]

hi
i m a student nd need to write a program to input coefficients of a quadratic equation and output its roots .
There is some problem in this , i tried several variations but it is not working.
Please check and let me know what's wrong and how to fix it...
#include <stdio.h>
#include <conio.h>
#include <math.h>

main()
{
float a,b,c,d,r1,r2;

printf("Enter the coefficients ...");
scanf("%f %f %f",&a,&b,&c);

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

if (!d<0)
{
if (d=0)
{
r1=((-b)/(2*a));
r2=r1;
}
else
// if (d>0)
{
r1=((-b+sqrt(d))/(2*a));
r2=((-b-sqrt(d))/(2*a));
}

}

printf("%f %f",r1,r2);

getch();
return 0;

}

[Savage]

This:

if (d=0)

is your problem.You are using assigment operator instead of eqaulity operator which is ==

Also don't use main(),use int main becasue that's what standard says you should use.

[JosAH]

... and this:

if (!d<0)
 

evaluates as if you had written this:

if((!d) < 0)
 

both (see the previous reply) are nonos.

kind regards,

Jos

[ginevralupin]

thnx so much,it works now !