(Distance expressed in terms of a parameter)
a. (i) Let P(t,1,2) and Q(4,4,6) be two points, where t is a real parameter. Obtain an expression for PQ2 in terms of t.
b. (ii) Determine the value(s) of t for which PQ equals 5 units.
c. (iii) How many distinct points P satisfy the condition obtained in part (ii)? Justify your answer.