Find explicit formulas (no sup or inf) for the endpoints of the interval in Eq. (11.3.36) for

Question:

Find explicit formulas (no sup or inf) for the endpoints of the interval in Eq. (11.3.36) for the following special cases:
a. c0 = 1 and c1 = x > 0.
b. c0 = 1 and c1 = x < 0.
In both cases the endpoints are of the form plus or minus linear functions of x that depend on the lengths of the sides of the rectangular joint confidence set.