I am new to C programming and having a hard time writing this program. If somebody can help it would great. This program ask the user for initial velocity and initial angle, then must calculate the max distance, max height and total travel time. The "requirements " must use at least 3 function not including the main function.

Code:

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int totaltraveltime(float velocity,float angle,float gravity);
int peakheight(float velocity,float angle,float gravity);
int range(float velocity,float angle,float gravity);
int main(void)
{
float initial_velocity=0;
float initial_angle=0;
float gravity=9.8;
float max_distance;
float max_height;
float duration;
printf("please enter initial velocity\n");
scanf("%f",&initial_velocity);
printf("please enter initial angle\n");
scanf("%f",&initial_angle);
max_distance = range(initial_velocity,initial_angle,gravity);
max_height = peakheight(initial_velocity,initial_angle,gravity);
duration = totaltraveltime(initial_velocity,initial_angle,gravity);
system("PAUSE");
return 0;
}
int totaltraveltime(float velocity,float angle)
{
duration= 2*((initial_velocity)*sin(initial_angle))/gravity;
return duration;
}
int peakheight(float velocity,float angle,float gravity)
{
max_height=((initial_velocity)*sin(pow)(initial_angle))/(2*gravity);
return max_height;
}
int range(float velocity,float angle,float gravity)
{
max_distance=((pow)(initial_velocity)*sin(2*initial_angle))/gravity;
return max_distance;
}