What do the mathematical symbols u, n, f and lg stand for in the text? What are the characters (-1, 10) and (1,1) on the axis?
U is an alliance. N is the intersection point. And f can't be interpreted separately ... usually f(x), which means that the functional relationship about x (-1, 10) means that the open interval from negative 1 to 10 does not include-1 and10 ...