the code is pretty much a mess because i've been trying everything to figure this out on my own. every time i compile and test the program, no matter what values i put in i end up with 0.0 for the acceleration answer.

i needed at least 1 user defined function for the problem i'm doing or else it would all be in the main.


Code:
#include <stdio.h>
double calc_answer(double, double, double); /*User defined function*/
double show_answer(double); /*User defined function*/
int main(void)
{
        double vi=0, /*initial velocity input in meters per second*/
        vf=0, /*final velocity input in meters per second*/
        time=0, /*time input in seconds*/
        accel1=0, /*acceleration calculation*/
        accel=0; /*acceleration output in meters per second squared*/

        printf("\n All values in seconds, meters per second, or meters per
second squared");
        printf("\n Please enter the initial velocity:"); /*input initial
velocity*/
        scanf("%lf", &vi);
        printf("\n Please enter the final velocity:"); /*input final
velocity*/
        scanf("%lf", &vf);
        printf("\n Please enter the time:"); /*input time*/
        scanf("%f", &time);

        calc_answer(vi, vf, time);
        show_answer(accel);
        return(vi, vf, time);
}
double calc_answer(double vi, double vf, double time)
{
        double accel1, /*acceleration part 1*/
        accel; /*final acceleration calculation value*/
        accel1 = vf-vi; /*Calculation of acceleration part 1*/
        accel = accel1/time; /*final calculation of acceleration*/
        return(accel);
}
double show_answer(double accel)
{
        printf("\n The acceleration is %.1lf \n\n\n\n", accel);
        return;
}
any help will be greatly appreciated.