An arithmetic sequence has and common difference . What is ?
08 Sequences and Recurrences Online Quiz Questions
Use this free practice quiz with 20 questions to review 08 Sequences and Recurrences, test your knowledge, and prepare for your next test or exam.
For the homogeneous recurrence an=4an−1−3an−2, which is the correct general solution?
- A
an=A+B3n
- B
an=(A+Bn)3n
- C
an=A2n+B3n
- D
an=A+B2n
Let sn count lists with entries from {1,2,3} whose entries sum to n, with s0=1 and sn=0 for n<0. What is s4?
- A
4
- B
6
- C
7
- D
9
Select all statements that are correct about recurrence relations.
- A
A recurrence generally needs enough initial conditions to determine a unique sequence.
- B
Every recurrence has a closed formula that is easier to find than the recurrence itself.
- C
A recurrence can arise by partitioning counted objects into disjoint cases.
- D
A second-order recurrence always requires exactly three initial values.
Select all correct statements about solving nonhomogeneous linear recurrences with constant coefficients.
- A
The homogeneous solution alone always solves the nonhomogeneous recurrence.
- B
The general solution combines a homogeneous solution with a particular solution.
- C
A polynomial forcing term can motivate a polynomial particular-solution trial.
- D
A trial form that duplicates a homogeneous solution should be used unchanged.
True or false: A recurrence relation without sufficient initial conditions generally fails to determine a unique sequence.
- A
True
- B
False
True or false: The recurrence T(n)=2T(n/2)+cn models merge sort and has running time O(nlogn).
- A
True
- B
False
A sequence is defined by a0=2 and an=an−1+3 for n≥1. Enter the exact value of a5.
What is the order of the recurrence an=5an−1−2an−2+7? Enter the exact integer.
Using F0=0, F1=1, and Fn=Fn−1+Fn−2 for n≥2, complete the statement: F4=.
Construct a recurrence for the number of tilings of a 1×n board using squares of length 1 and dominoes of length 2. Define the counted quantity, justify the recurrence by considering the final tile, and give the necessary initial conditions.
What is the sum ∑k=032⋅3k?
- A
54
- B
80
- C
81
- D
162
An arithmetic sequence has a0=4 and common difference d=3. What is ∑k=04ak?
- A
40
- B
45
- C
50
- D
55
What is the order of the recurrence an=4an−1−an−2?
- A
First order
- B
Second order
- C
Third order
- D
Fourth order
Evaluate the infinite geometric series ∑k=0∞6(31)k.
- A
6
- B
8
- C
9
- D
12
What is the value of ∑k=14(k1−k+11)?
- A
43
- B
54
- C
65
- D
1
True or false: A recurrence relation without sufficient initial conditions generally determines a unique sequence.
- A
True
- B
False
Given a0=1 and an=2an−1+3 for n≥1, enter the value of a3.
In solving a nonhomogeneous linear recurrence, what is the standard name for the additional solution combined with the homogeneous solution to obtain the general solution?
Rewrite the sum k=1∑nak−1 using the index j=k−1: \displaystyle\sum_{j=}^aj.