This is Discrete Math, please help with 3 and 4

d prove that your formula is valid. f (0) = 0, f(n) = 2f(n - 2) forn 2 1. f(0) = 1, f(n) = f(n - 1) - 1 forn 21. d. f(0) = 2, f (1) = 3, f (n) = f(n - 1) - 1 for n 2 2. f (0) = 1, f (1) = 2, f (n) = 2f(n - 2) forn 2 2. - f(0) = 1, f(n) = 3f(n - 1) if n is odd and n > 1 and f (n) = 9f (n - 2) if n is even and n > 2. 3. (You'll need to remember matrix multiplication for this question.) Let A = . Show that An = In+1 fn where fo denote the terms of the Fibonacci numbers. fn-1 Give a recursive definition of a. the set of even integers. . the set of positive integers congruent to 2 modulo 3. c. the set of positive integers not divisible by 5. 5. The reversal of a string is the string consisting of the symbols of the string in reverse order. The revers: string w is denoted by wh. Find the reversal of the following bit strings: a. 0101 b. 1 1011 versal of a string. [Hint: First define the reversal of the empty st n, and express the reversal of