Pythagoras Theorem program

[gibsonj338]

Two cars A and B leave an intersection at the same time. Car A travels west at an average
speed of x miles per hour and car B travels south at an average speed of y miles per hour.
Write a program that prompts the user to enter:
1. The average speed of Car A and Car B as two separate input statements.
2. The elapsed time (in hours and minutes, separated by a space) after the cars leave
the intersection.
o Ex: For two hours and 30 minutes, 2 30 would be entered
The program then outputs:
1. The (shortest) distance between the cars.
Hint:
You will need to use the Pythagorean theorem to calculate the distance.

Here is what I wrote so far and cannot for the life of me figure out what I am doing wrong. Any help would he highly helpful.

  /*   CS161 Winter 2019
Assignment 3
Joshua Gibson

Sources:
https://www.mathsisfun.com/pythagoras.html

Purpose:
This program calculates the shortest diatance between car A and car B from user inputs
of speed of car A (mph), speed of car B (mph), and elapsed time (in hours and minutes)

Formula / Assumptions
// (shortest_distance_traveled)^2 = [(speed_of_car_A + speed_of_car_B)/2]^2 + (elapsed_time)^2
*/

#include "stdafx.h"
#include <iostream>
#include <math.h>
using namespace std;

int main()
{
	double shortest_distance_traveled = 0;
	double speed_of_car_A = 0;
	double speed_of_car_B = 0;
	double elapsed_time = 0;

	shortest_distance_traveled = sqrt((speed_of_car_A + speed_of_car_B) / 2 * (speed_of_car_A + speed_of_car_B) / 2 + elapsed_time * elapsed_time);

	cout << "Enter the speed of car A (mph): ";
	cin >> speed_of_car_A;
	cout << "Enter the speed of car B (mph): ";
	cin >> speed_of_car_B;
	cout << "Enter the time the cars traveled (in hours and minutes seperated by a space): ";
	cin >> elapsed_time;
	cout << "The shortest distance traveled between car A and car B: ";
	cout << shortest_distance_traveled << endl;

	return 0;

}

[keskiverto]

You do compute a value on line 28 and store it into variable 'shortest_distance_traveled'.
You do show that value on line 37.
Nothing did change that value on lines 29-36.

On line 28 the three other variables have value 0.
How much is sqrt((0+0)/2*(0+0)/2+0*0)?

In other words, the order the operations are executed is important.


How far does car A travel within elapsed_time? Isn't distance==time*speed?
Pythagoras has three distances. Your equation has something else.


You say: "in hours and minutes" but you read only one double value.
Are hours not an integer? Are minutes not an integer?

[coder777]

As keskiverto mentioned: You calculate the formula before the variables have usefull values. So the line 28 must be moved after line 35 and before line 37.