Sets, Relations...

If f(x)• f(1/x) = f(x) + f(1/ x) and f(4) = 65,then f(6) is equal to

If f(x) = ax + b, g(x) = cx + d, then f{g(x)} = g {f(x)} is equivalent to

If Q denotes the set of all rational numbers and f (p/q) = √p² - √q² for any p/q ϵ Q, then observe the following statements.
I. f(p/q) is real for each p/q ϵ Q
II. f(p/q) is a complex number for each p/q ϵ Q

If f : R → R is given by

If f(x) = (a-xⁿ)^1/n , where a > 0 and n ϵ N, then fof(x) is equal to

If f : (2, 3) → (0,1) is defined by f(x) = x - [x] , then f^-1(x) is equal to

If X = {4ⁿ - 3n - 1: n ∈ N} and Y = {9(n - 1): n ∈ N}, where N is the set of natural numbers, then X ∪ Y is equal to

The set A = {x : |2x + 3| < 7} is equal to the set

If the number of elements of the sets A and B are p and q, respectively. Then, the number of relations from the set A to the set B is