C++ gradient function returning false value

Question

User will enter 4 different points and findSlope (function) will calculate the value for slope and return back the value to be cout in main function.

But when I ran the program, it had logic error for slope value. Any idea why?

#include <iostream>
#include <iomanip>
using namespace std;

float findSlope(float a,float b,float c,float d)
{
    return (d-b/c-a);
}   
int main()
{
    float slope,p1,q1,p2,q2;

    cout << "Enter x1: ";
    cin >> p1;
    cout << "Enter y1: ";
    cin >> q1;
    cout << "Enter x2: ";
    cin >> p2;
    cout << "Enter y2: ";
    cin >> q2;

    slope=findSlope(p1,q1,p2,q2);
    cout << "Point1" << "\t\tPoint2" << "\t\tSlope" << endl;
    cout << fixed << setprecision(2) << p1 << "," << q1 << "\t" << p2 << "," << q2 << "\t" << slope << endl;

    return 0;
}

Answer 1

return (db/ca);

Please look at order of operations again. What you intended to calculate was (db)/(ca) . Right now you are calculating d - (b/c) - a . This is a basic mathematical thing and your calculator would most likely give you the same output if you had tried to check this yourself.

Answer 2

Your slope function has

return (d-b/c-a)

did you mean

return ((d-b)/(c-a))

Operator precedence will do the division first, without the brackets.