In my math programming class I have an assignment to find the slope intercept formula (y2 - y1) / (x2 - x1) which is the m of the formula y = mx + b.

I have to find 2 slope intercept equations and make an if-statement or multiple if-statements to see if the lines intercept, don't intercept, or are the same line. Pretty easy right? I have 2 error LNK2019 errors. There are my errors and my program is copy pasted underneath. Can anyone help me out please??


1>main_program.obj : error LNK2019: unresolved external symbol "float __cdecl Other_Slope_intercept_formula(float *,float *)" (?Other_Slope_intercept_formula@@YAMPAM0@Z) referenced in function _main

1>main_program.obj : error LNK2019: unresolved external symbol "float __cdecl Slope_intercept_formula_of_the_lines(float *,float *)" (?Slope_intercept_formula_of_the_lines@@YAMPAM0@Z) referenced in function _main

1>c:\users\zvjezdan\documents\visual studio 2010\Projects\project2_gamephysics\Debug\project2_gamephysics.exe : fatal error LNK1120: 2 unresolved externals

#include <iostream>
#include <string>
#include <cmath>
#include <algorithm>
using namespace std;
int main()
{
	int formula1[2];
	int formula2[2];
	int formula3[2];
	int formula4[2];
	int B, b;
	cout << "Welcome to the program.  ^_^" << endl;
	cout << endl;
	cout << "What is the X number for the first slope intercept formula? ";
	cin >> formula1[0];
	cout << endl;
	cout << "What is the Y number for the first slope intercept formula? ";
	cin >> formula1[1];
	cout << endl;
	cout << "What is the X number for the second slope intercept formula? ";
	cin >> formula2[0];
	cout << endl;
	cout << "What is the Y number for the second slope intercept formula? ";
	cin >> formula2[1];
	cout << endl;
	float Slope_intercept_formula_of_the_lines( float *formula1, float *formula2);
	{
		cout <<  " The slope intercept formula is (y2 - y1) / (x2 - x1) which is the M in the formula y = mx + b" << endl;
		cout << endl;
		cout << "That being the case, your Slope Intercept of the First Problem is: " << (formula2[1] - formula1[1]) /(formula2[0] - formula1[0]) << "x" << endl;
		cout << endl;
	};
	cout << "For the formula y = mx + b, your m is: " << Slope_intercept_formula_of_the_lines << "x" << endl;
	cout << endl;
	cout << "What do you want b to be? ";
	cin >> B;
	cout << endl;
	cout << "What is the X number for the first slope intercept formula? ";
	cin >> formula3[0];
	cout << endl;
	cout << "What is the Y number for the first slope intercept formula? ";
	cin >> formula3[1];
	cout << endl;
	cout << "What is the X number for the second slope intercept formula? ";
	cin >> formula4[0];
	cout << endl;
	cout << "What is the Y number for the second slope intercept formula? ";
	cin >> formula4[1];
	cout << endl;
	float Other_Slope_intercept_formula( float *formula3, float *formula4);
	{
		cout <<  " The slope intercept formula is (y2 - y1) / (x2 - x1) which is the M in the formula y = mx + b" << endl;
		cout << endl;
		cout << "That being the case, your Slope Intercept of the First Problem is: " << (formula4[1] - formula3[1]) /(formula4[0] - formula3[0]) << "x" << endl;
		cout << endl;
	};

	cout << "For the formula y = mx + b, your m is: " << Other_Slope_intercept_formula << "x" << endl;
	cout << endl;
	cout << "What do you want b to be? ";
	cin >> b;
	cout << endl;

	if (Slope_intercept_formula_of_the_lines == Other_Slope_intercept_formula && B == b)
	{
		cout << "The Lines are the same line. " << endl;
		cout << endl;

	}
	else if (Slope_intercept_formula_of_the_lines == Other_Slope_intercept_formula && B != b)
	{
		cout << "The lines are parallel." << endl;
		cout << endl;
	}
	else if (Slope_intercept_formula_of_the_lines != Other_Slope_intercept_formula && B == b)
	{
		cout << "The lines intersect at B." << endl;
		cout << endl;
	}
	else if(Slope_intercept_formula_of_the_lines != Other_Slope_intercept_formula && B != b)
	{
		cout << "The lines intersect." << endl;
		cout << endl;
	}
	system("pause");
	return 0;
}

Recommended Answers

Hmm... So many unknown function calls! Anyway, when an external link error occurs, you need to check if the libraries you include in your program are installed correctly. I don't know about your "algorithm" library.

Also, the line

int formula3[2];
...
...
float Other_Slope_intercept_formula( float *formula3, …
Jump to Post

Hmm.. You are still using syntax wrong... In line 23 & 43, do you want to declare a variable or a function?

float slope1((y2 - y1) / (x2 - x1));

If you want it as a variable, you should do it as

float slope1 …
Jump to Post

All 5 Replies

I still need helpppp

Hmm... So many unknown function calls! Anyway, when an external link error occurs, you need to check if the libraries you include in your program are installed correctly. I don't know about your "algorithm" library.

Also, the line

int formula3[2];
...
...
float Other_Slope_intercept_formula( float *formula3, float *formula4);

don't seem to be correct. If you declare "formular3" as int array, why do you use it as float pointer? Oh, are you sure that the line is "calling" a function or "declaring" a function? If you are calling a function and pass value by "reference" you need to call it as...

Other_Slope_intercept_formula(formula3, formula4);  // Please correct me if I'm wrong. Not use C++ for a long time.

Also, that mean you should declare formular# variables as float array, and the function accept float array variables as well.

I don't think it would work, but I have fixed it. Here is my code.

#include <iostream>
#include <string>
#include <cmath>
#include <algorithm>
using namespace std;
int main()
{
	int x1,y1,x2,y2,x3,y3,x4,y4,B,b;
	cout << "Welcome to the program.  ^_^" << endl;
	cout << endl;
	cout << "What is the X number for the first slope intercept formula? ";
	cin >> x1;
	cout << endl;
	cout << "What is the Y number for the first slope intercept formula? ";
	cin >> y1;
	cout << endl;
	cout << "What is the X number for the second slope intercept formula? ";
	cin >> x2;
	cout << endl;
	cout << "What is the Y number for the second slope intercept formula? ";
	cin >> y2;
	cout << endl;
	float slope1((y2 - y1) / (x2 - x1));
	cout << "The slope for the first equation is: " << slope1 << "x" << endl; 
	cout << endl;
	cout << "For the formula y = mx + b, your m is: " << slope1 << "x" << endl;
	cout << endl;
	cout << "What do you want b to be? ";
	cin >> B;
	cout << endl;
	cout << "What is the X number for the first slope intercept formula? ";
	cin >> x3;
	cout << endl;
	cout << "What is the Y number for the first slope intercept formula? ";
	cin >> y3;
	cout << endl;
	cout << "What is the X number for the second slope intercept formula? ";
	cin >> x4;
	cout << endl;
	cout << "What is the Y number for the second slope intercept formula? ";
	cin >> y4;
	cout << endl;
	float slope2((y4 - y3) / (x4 - x3));
	cout << "The slope intercept for the second equation is: " << slope2 << "x" << endl;
	cout << endl;
	cout << "For the formula y = mx + b, your m is: " << slope2 << "x" << endl;
	cout << endl;
	cout << "What do you want b to be? ";
	cin >> b;
	cout << endl;
	if (slope1 == slope2 && B == b)
	{
		cout << "The Lines are the same line. " << endl;
		cout << endl;

	}
	else if (slope1 == slope2 && B != b)
	{
		cout << "The lines are parallel." << endl;
		cout << endl;
	}
	else if (slope1 != slope2 && B == b)
	{
		cout << "The lines intersect at B." << endl;
		cout << endl;
	}
	else if(slope1 != slope2 && B != b)
	{
		cout << "The lines intersect." << endl;
		cout << endl;
	}
	system("pause");
	return 0;
}

Hmm.. You are still using syntax wrong... In line 23 & 43, do you want to declare a variable or a function?

float slope1((y2 - y1) / (x2 - x1));

If you want it as a variable, you should do it as

float slope1 = (y2 - y1) / (x2 - x1);

The same should be applied to line 43.

Hmm.. You are still using syntax wrong... In line 23 & 43, do you want to declare a variable or a function?

float slope1((y2 - y1) / (x2 - x1));

If you want it as a variable, you should do it as

float slope1 = (y2 - y1) / (x2 - x1);

The same should be applied to line 43.

There shouldn't be anything wrong with that. It's an explicit variable declaration and initialization, no different than:

int someInt(15);

>>...but I have fixed it...
If there is an issue, which I doubt, the issue must be something else.

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