So for these values of does not exist.
(3) The maximum value of is , and this occurs when
So the minimum positive value of is at these values of .
Similarly, the maximum negative value of is at
(a) Now let's suppose that the function to give the graph is of the form
Using (3) above, the minimum positive value of is . So, from the graph, .
The first of these is when . So from (3) again,
The next is when . So
Subtracting these two equations, we get
So the function is
(b) Now start with the fact that and see if you can work out similar statements to numbers (1) - (3) above. Then set up the function and work out the values of in the same way.