im getting this warnings but i've not solved it yet, when i compile the program, in the 400 line , these 3 lines are gives warning, and it makes me unhappy.I want perfect.

Some parts of my program

Code:

#include <stdio.h>
#include <math.h>
..
float delta,r1,r2,b,a,c,ii1,ii2=0;
..
if (delta>0)
{
w -> r1=(b-sqrt(delta))/(2*a);
w -> r2=(b+sqrt(delta))/(2*a);
printf(" r1=%f\n r2=%f\n\n\n",r1,r2);
}
.....
else
{
r1=b/(2*a);
w -> ii1=(sqrt(-delta))/(2*a);
// r2=-b/(2*a)
//ii2=sqrt(-delta)/(2*a));
printf(" r1=%f+i%f\n r2=%f-i%f\n\n\n",r1,ii1,r1,ii1);
}
.....
return 0;

here is the warnings

warning C4244: '=' : conversion from 'double ' to 'float ', possible loss of data

there are three same warnings

thanks for reading my topic.Help me plz