Consider a geometric progression whose first term is 12 and whose common ratio is r=m+43m−2, where m is a real parameter.
a. (i) Determine all real values of m for which the corresponding infinite series converges.
b. (ii) For the values of m found in part (i), obtain an expression for the sum to infinity in terms of m.
c. (iii) Hence find the exact sum when m=2.