Free Practice Quiz Question List

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.

20 questions
01
Choose one
1 point

An arithmetic sequence has a0=3a_0=3 and common difference d=4d=4. What is ∑k=04ak\sum_{k=0}^{4}a_k?

  1. A

    45

  2. B

    55

  3. C

    60

  4. D

    66

02
Choose one
1 point

For the homogeneous recurrence an=4an−1−3an−2a_n=4a_{n-1}-3a_{n-2}, which is the correct general solution?

  1. A

    an=A+B3na_n=A+B3^n

  2. B

    an=(A+Bn)3na_n=(A+Bn)3^n

  3. C

    an=A2n+B3na_n=A2^n+B3^n

  4. D

    an=A+B2na_n=A+B2^n

03
Choose one
1 point

Let sns_n count lists with entries from {1,2,3}\{1,2,3\} whose entries sum to nn, with s0=1s_0=1 and sn=0s_n=0 for n<0n<0. What is s4s_4?

  1. A

    4

  2. B

    6

  3. C

    7

  4. D

    9

04
Choose all
1 point

Select all statements that are correct about recurrence relations.

  1. A

    A recurrence generally needs enough initial conditions to determine a unique sequence.

  2. B

    Every recurrence has a closed formula that is easier to find than the recurrence itself.

  3. C

    A recurrence can arise by partitioning counted objects into disjoint cases.

  4. D

    A second-order recurrence always requires exactly three initial values.

05
Choose all
1 point

Select all correct statements about solving nonhomogeneous linear recurrences with constant coefficients.

  1. A

    The homogeneous solution alone always solves the nonhomogeneous recurrence.

  2. B

    The general solution combines a homogeneous solution with a particular solution.

  3. C

    A polynomial forcing term can motivate a polynomial particular-solution trial.

  4. D

    A trial form that duplicates a homogeneous solution should be used unchanged.

06
True or false
1 point

True or false: A recurrence relation without sufficient initial conditions generally fails to determine a unique sequence.

  1. A

    True

  2. B

    False

07
True or false
1 point

True or false: The recurrence T(n)=2T(n/2)+cnT(n)=2T(n/2)+cn models merge sort and has running time O(nlog⁡n)O(n\log n).

  1. A

    True

  2. B

    False

08
Written response
1 point

A sequence is defined by a0=2a_0=2 and an=an−1+3a_n=a_{n-1}+3 for n≥1n\ge 1. Enter the exact value of a5a_5.

09
Written response
1 point

What is the order of the recurrence an=5an−1−2an−2+7a_n=5a_{n-1}-2a_{n-2}+7? Enter the exact integer.

10
Fill in the blank
1 point

Using F0=0F_0=0, F1=1F_1=1, and Fn=Fn−1+Fn−2F_n=F_{n-1}+F_{n-2} for n≥2n\ge 2, complete the statement: F4=F_4=.

11
Open ended
1 point

Construct a recurrence for the number of tilings of a 1×n1\times 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.

12
Choose one
1 point

What is the sum ∑k=032⋅3k\sum_{k=0}^{3}2\cdot 3^k?

  1. A

    54

  2. B

    80

  3. C

    81

  4. D

    162

13
Choose one
1 point

An arithmetic sequence has a0=4a_0=4 and common difference d=3d=3. What is ∑k=04ak\sum_{k=0}^{4}a_k?

  1. A

    40

  2. B

    45

  3. C

    50

  4. D

    55

14
Choose one
1 point

What is the order of the recurrence an=4an−1−an−2a_n=4a_{n-1}-a_{n-2}?

  1. A

    First order

  2. B

    Second order

  3. C

    Third order

  4. D

    Fourth order

15
Choose one
1 point

Evaluate the infinite geometric series ∑k=0∞6(13)k\sum_{k=0}^{\infty}6\left(\frac{1}{3}\right)^k.

  1. A

    6

  2. B

    8

  3. C

    9

  4. D

    12

16
Choose one
1 point

What is the value of ∑k=14(1k−1k+1)\sum_{k=1}^{4}\left(\frac{1}{k}-\frac{1}{k+1}\right)?

  1. A

    34\frac{3}{4}

  2. B

    45\frac{4}{5}

  3. C

    56\frac{5}{6}

  4. D

    1

17
True or false
1 point

True or false: A recurrence relation without sufficient initial conditions generally determines a unique sequence.

  1. A

    True

  2. B

    False

18
Written response
1 point

Given a0=1a_0=1 and an=2an−1+3a_n=2a_{n-1}+3 for n≥1n\ge 1, enter the value of a3a_3.

19
Written response
1 point

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?

20
Fill in the blank
1 point

Rewrite the sum ∑k=1nak−1\displaystyle\sum_{k=1}^{n} a_{k-1} using the index j=k−1j=k-1: \displaystyle\sum_{j=}^aj a_j.