Question

C++ Code Needed for Lab!

Let l be a line in the x-y plane. If l is a vertical line, its equation is x = a for some real number a.

Suppose l is not a vertical line and its slope is m. Then the equation of l is y = mx + b, where b is the y-intercept.

If l passes through the point (x₀, y₀), the equation of l can be written as y - y₀ = m(x - x₀).

If (x₁, y₁) and (x₂, y₂) are two points in the x-y plane and x₁ ≠ x₂, the slope of line passing through these points is m = (y₂ - y₁)/(x₂ - x₁).

Instructions

Write a C++ program that prompts the user for two points in the x-y plane. Input should be entered in the following order:

• Input x₁
• Input y₁
• Input x₂
• Input y₂

The program:

1. Outputs the equation of the line
2. Uses if statements to determine and output whether the line is vertical, horizontal, increasing, or decreasing.

If l is a non-vertical line, output its equation in the form y = mx + b.

Note: Output all numbers with a precision of two decimal places.

Answer 1

int main()
{
    int x1,y1,x2,y2;
    float m,b;
    cin>>x1;
    cin>>y1;
    cin>>x2;
    cin>>y2;
    if(x1 == x2){
        cout<<"x = "<<x1<<endl;
    }
    else if(y1 == y2){
        cout<<"y = "<<y1<<endl;
    }
    else{
        m = (float)(y2-y1)/(x2-x1);
        b = y2 - m*x2;
        cout<<"y = "<<m<<"x + ("<<b<<")"<<endl;
    }

    return 0;
}