Problem with Math. h functions

Question

always receive as a result: 0.000000

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

int main()

{

   float x1, y1, x2, y2, resultado;

   printf("insira x1:");
   scanf("%f", &x1);
   printf("insira y1:");
   scanf("%f", &y1);
   printf("insira x2:");
   scanf("%f", &x2);
   printf("insira y2:");
   scanf("%f", &y2);

   resultado = sqrtf((powf((x2 - x1), 2)) + (powf((y2 - y1), 2)));

   printf("resultado:");
   printf("%f\n", &resultado);

   printf("pressione qualquer tecla para sair.");
   getch();

   return 0;

}

Answer 1

The calculation is correct, your problem is just in time to display the value on the screen. When compiling the code I have the following Warning:

a.c: In Function main:
a.c:22:4: Warning: format %f expects argument of type double, but argument 2 has type float * [-Wformat=]

printf("%f\n", &resultado);
    ^

Two clear mistakes here.

1. The function does not wait for a pointer to the value, but rather the value itself. Use resultado in place of &resultado.

2. The format %f gets a double, not a float in the printf (note that in the scanf he does receive a float). Use:

   printf("%f\n", (double)resultado);
   

   Or better yet, declare all your variables double and use %lf in the scanf.

Always Compile with connected warnings!

Answer 2

It seems that the code has some basic problems. How about?

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

int main()

{

    float x1, y1, x2, y2, resultado;

    printf("insira x1:");
    scanf("%f", &x1);
    printf("insira y1:");
    scanf("%f", &y1);
    printf("insira x2:");
    scanf("%f", &x2);
    printf("insira y2:");
    scanf("%f", &y2);

    resultado = sqrtf((powf((x2 - x1), 2)) + (powf((y2 - y1), 2)));

    printf("resultado:");
    printf("%f\n", resultado);  // aqui

    return 0;

}