You can use a iterative method for example bisection

#include <stdio.h>
main()
{
int n;
float eval 1.0 x1 0 x2 n x; //trying to locate root between x1 0 and x2 n and giving a initial dummy value to eval
x (x1+x2)/2;
printf( Enter value for n n n );
scanf( d &n);
while((eval > 0.0001 )||( eval < -0.0001) ) { //you can change accuracy by changing 0.0001 to smaller value
eval x*x-n;
printf( eval f t eval); //printf to keep track not necessary
if(eval>0){
x2 x;
x (x2+x1)/2 ;
printf( x f t x); //printf to keep track not necessary
}
else {
x1 x ;
x (x1+x2)/2 ;
printf( x f t x); //printf to keep track not necessary
}
printf( n n );
}
printf( the root is f x);


}