A graph of a linear function f(x) = kx+b is a line. There are various types of its construction (use radio buttons to select one).
First, by 2 points. Define two points of the line by clicking twice on the coordinate system. Solve an equation set y1=kx1+b and y2=kx2+b where (x1, y1) and (x2, y2) the coordinates of plotted points for variables k and b. Draw a line through the points.
Second, by points of intersection with axes. Define a point by clicking on axis X and another on axis Y. Then a line through the points is draw. This type is similar to the previous one.
Third, by a point and an angle between the line and axis X. Define a point by mouse click and an angle by mouse motion. A line is drawn. The coefficient k is a tangent of the angle.