Hello everyone I post last night with this same code, and I got a lot of advice. But there are 3 more errors that persist after I changed the code a bit. Anyone know whats wrong?

Here are the errors:

1>------ Build started: Project: circle, Configuration: Debug Win32 ------

1>Compiling...

1>circle.cpp

1>c:\users\emcy\documents\visual studio 2008\projects\circle\circle\circle.cpp(39) : error C2664: 'diameter' : cannot convert parameter 1 from 'double (__cdecl *)(double,double,double,double)' to 'double'

1> Context does not allow for disambiguation of overloaded function

1>c:\users\emcy\documents\visual studio 2008\projects\circle\circle\circle.cpp(40) : error C2664: 'circumference' : cannot convert parameter 1 from 'double (__cdecl *)(double,double,double,double)' to 'double'

1> Context does not allow for disambiguation of overloaded function

1>c:\users\emcy\documents\visual studio 2008\projects\circle\circle\circle.cpp(41) : error C2664: 'area' : cannot convert parameter 1 from 'double (__cdecl *)(double,double,double,double)' to 'double'

1> Context does not allow for disambiguation of overloaded function

1>Build log was saved at "file://c:\Users\Emcy\Documents\Visual Studio 2008\Projects\circle\circle\Debug\BuildLog.htm"

1>circle - 3 error(s), 0 warning(s)

========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

And here is the code:

#include <iostream>

#include <cmath>

using namespace std;

double radius(double x, double y, double xs, double ys);

double diameter(double x);

double circumference(double x);

double area(double x);

const double pi = 3.141;

int main()

{

double centerX;

double centerY;

double pointX;

double pointY;

double radiusMain;

double diameterMain;

double circumferenceMain;

double areaMain;

cout << "This program will calculate the radius, diameter, circumference and area \n of a circle if the user gives the locaction of the center point and \n a point on the circle."<< endl;

system("pause");

system("cls");

cout << "Enter the x coordinate for the center of the circle. \n" << endl;

cin >> centerX;

cout << "Enter the y coordinate for the center of the circle. \n" << endl;

cin >> centerY;

cout << "Now enter the x coordinate for any point on the circle. \n" << endl;

cin >> pointX;

cout << "Now enter the y coordinate for any point on the circle. \n" << endl;

cin >> pointY;

radiusMain = radius(centerX, centerY, pointX, pointY);

diameterMain = diameter(radius);

circumferenceMain = circumference(radius);

areaMain = area(radius);

cout << "The radius of the circle is " << radiusMain << endl;

cout << "The diameter of the circle is " << diameterMain << endl;

cout << "The circumference of the circle is " << circumferenceMain << endl;

cout << "The area of the circle is " << areaMain << endl;

return 0;

}

double radius(double x, double y, double xs, double ys)

{

double radiusfunc;

radiusfunc = sqrt(pow((x-xs),2) + pow((y-ys),2));

return radiusfunc;

}

double diameter(double x)

{ double diameterfunc;

diameterfunc = x * 2;

return diameterfunc;

}

double circumference(double x)

{

double circumferencefunc;

circumferencefunc = 2 * pi * x;

return circumferencefunc;

}

double area(double x)

{

double areafunc;

areafunc = pi * pow(x,2);

return areafunc;

}