7. Consider the function f : N N given by f(n) 3n +1, if n is odd (a) Is f injective? (b) Is f surjective? (c) For f(12), how many iterations of the function does it require until the output is 1? (d) For any initial n, does the process of repeatedly plugging in the answer eventually reach 1? 7. Consider the function f : N N given by f(n) 3n +1, if n is odd (a) Is f injective? (b) Is f surjective? (c) For f(12), how many iterations of the function does it require until the output is 1? (d) For any initial n, does the process of repeatedly plugging in the answer eventually reach 1