Solve the equation
where 0 < a, b < 1 and a + b < 1, in the special cases:
(i) a = b (ii) a = 1/2, b=1/4 (iii)a = 1/2, b=1/3 .
Although you can find exact solutions in special cases like (i) and
(ii) it soon becomes apparent that generally you will
need to use a numerical method for finding approximate solutions.