Recurrence Relations
This quiz covers fundamental concepts and techniques related to recurrence relations, a core topic in combinatorics and discrete mathematics.
Questions
What is the general form of a linear homogeneous recurrence relation of order k?
- a_n = c_1 * a_{n-1} + c_2 * a_{n-2} + ... + c_k * a_{n-k}
- a_n = c_1 * a_{n-1} + c_2 * a_{n-2} + ... + c_k * a_{n+k}
- a_n = c_1 * a_{n+1} + c_2 * a_{n+2} + ... + c_k * a_{n+k}
- a_n = c_1 * a_{n-1} + c_2 * a_{n-2} + ... + c_k * a_{n-1}
Which of the following is a characteristic equation for the recurrence relation a_n = 3 * a_{n-1} - 2 * a_{n-2}?
- r^2 - 3 * r + 2 = 0
- r^2 + 3 * r + 2 = 0
- r^2 - 3 * r - 2 = 0
- r^2 + 3 * r - 2 = 0
What is the general solution to the recurrence relation a_n = 3 * a_{n-1} - 2 * a_{n-2} with initial conditions a_0 = 1 and a_1 = 2?
- a_n = 2^n + 1
- a_n = 2^n - 1
- a_n = 3^n + 1
- a_n = 3^n - 1
Which of the following is a recurrence relation for the Fibonacci sequence?
- F_n = F_{n-1} + F_{n-2}
- F_n = F_{n-1} - F_{n-2}
- F_n = 2 * F_{n-1} - F_{n-2}
- F_n = 2 * F_{n-1} + F_{n-2}
What is the generating function for the sequence {1, 2, 4, 8, 16, ...}?
- G(x) = 1 / (1 - 2 * x)
- G(x) = 1 / (1 + 2 * x)
- G(x) = 1 / (1 - 4 * x)
- G(x) = 1 / (1 + 4 * x)
Which of the following is a recurrence relation for the number of ways to climb n stairs, if you can take either one step or two steps at a time?
- f(n) = f(n-1) + f(n-2)
- f(n) = f(n-1) - f(n-2)
- f(n) = 2 * f(n-1) - f(n-2)
- f(n) = 2 * f(n-1) + f(n-2)
What is the asymptotic behavior of the solution to the recurrence relation a_n = 2 * a_{n-1} - 3 * a_{n-2} as n approaches infinity?
- a_n ~ 2^n
- a_n ~ 3^n
- a_n ~ (-2)^n
- a_n ~ (-3)^n
Which of the following is a recurrence relation for the number of ways to partition a set of n elements into k non-empty subsets?
- S(n, k) = S(n-1, k) + S(n-1, k-1)
- S(n, k) = S(n-1, k) - S(n-1, k-1)
- S(n, k) = 2 * S(n-1, k) - S(n-1, k-1)
- S(n, k) = 2 * S(n-1, k) + S(n-1, k-1)
What is the generating function for the sequence {1, 1, 2, 3, 5, 8, 13, ...}, where each term is the sum of the two previous terms?
- G(x) = 1 / (1 - x - x^2)
- G(x) = 1 / (1 + x + x^2)
- G(x) = 1 / (1 - x + x^2)
- G(x) = 1 / (1 + x - x^2)
Which of the following is a recurrence relation for the number of ways to make change for n cents using coins of denominations 1, 5, and 10 cents?
- C(n) = C(n-1) + C(n-5) + C(n-10)
- C(n) = C(n-1) - C(n-5) - C(n-10)
- C(n) = 2 * C(n-1) - C(n-5) + C(n-10)
- C(n) = 2 * C(n-1) + C(n-5) - C(n-10)
What is the asymptotic behavior of the solution to the recurrence relation a_n = 3 * a_{n-1} - 2 * a_{n-2} as n approaches infinity?
- a_n ~ 3^n
- a_n ~ 2^n
- a_n ~ (-3)^n
- a_n ~ (-2)^n
Which of the following is a recurrence relation for the number of ways to arrange n distinct objects in a row?
- P(n) = P(n-1) + 1
- P(n) = P(n-1) - 1
- P(n) = 2 * P(n-1) + 1
- P(n) = 2 * P(n-1) - 1
What is the generating function for the sequence {1, 4, 9, 16, 25, ...}?
- G(x) = 1 / (1 - 4 * x)
- G(x) = 1 / (1 + 4 * x)
- G(x) = 1 / (1 - 2 * x)
- G(x) = 1 / (1 + 2 * x)
Which of the following is a recurrence relation for the number of ways to color n balls using k colors, if each ball can be colored with any of the k colors?
- C(n, k) = C(n-1, k) + C(n-1, k-1)
- C(n, k) = C(n-1, k) - C(n-1, k-1)
- C(n, k) = 2 * C(n-1, k) + C(n-1, k-1)
- C(n, k) = 2 * C(n-1, k) - C(n-1, k-1)