For a particular commodity, the demand function is q = 120 , 000 p . a . find ε when p = 20 .

In the diagram, points d and e are marked by drawing arcs of equal size centered at b such that the arcs intersect ba and bc. then, intersecting arcs of equal size are drawn centered at points d and e. point p is located at the intersection of these arcs. based on this construction, m , and m