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May 2023 term · Machine Learning Foundations · BSCS2004

Machine Learning Foundations Quiz 2: 6 August 2023 (May 2023 term)

The IIT Madras BS Machine Learning Foundations (MLF) Quiz 2 paper sat on 6 Aug 2023, in the May 2023 term: 13 questions for 40 marks in 120 minutes. Every question is below with its answer. Take it as a timed mock test to be marked, or read it through first.

Questions
13
Marks
40
Duration
120 min
MSQ
3
Numerical
5
MCQ
5

Updated

Official paper: IIT M FOUNDATION AN2 EXAM QPF2 06 Aug 2023 · No negative marking.

Question 1

+3 marksOne or more correct options

Which among the following is/are true for a Hermitian matrix?

Select all that apply.

  1. A

    The eigenvalues of a Hermitian matrix are always real.

  2. B

    The diagonal elements of a Hermitian matrix are always real.

  3. C

    All symmetric matrices are Hermitian.

  4. D

    All Hermitian matrices are symmetric.

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Correct answers

  • A

    The eigenvalues of a Hermitian matrix are always real.

  • B

    The diagonal elements of a Hermitian matrix are always real.

Question 2

+3 marksOne or more correct options

Which of the following options are true?

Select all that apply.

  1. A

    A matrix that is both unitary and Hermitian must be a diagonal matrix.

  2. B

    A matrix that is both unitary and Hermitian need not be a diagonal matrix.

  3. C

    If matrix A is unitary, then A* is unitary.

  4. D

    If matrix A is unitary then, A* may not be unitary.

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Correct answers

  • B

    A matrix that is both unitary and Hermitian need not be a diagonal matrix.

  • C

    If matrix A is unitary, then A* is unitary.

Question 3

+3 marksOne or more correct options

Which among the following statements is/are true?

Select all that apply.

  1. A

    If a function is positive semidefinite, then it only has a global minimum.

  2. B

    If a function is positive semidefinite, then it has both global minimum and global maximum.

  3. C

    If a function is negative semidefinite, then it only has a global maximum.

  4. D

    If a function is negative semidefinite, then it has both global minimum and global maximum.

Show answer

Correct answers

  • A

    If a function is positive semidefinite, then it only has a global minimum.

  • C

    If a function is negative semidefinite, then it only has a global maximum.

Question 4

+3 marksNumerical answer
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Correct answer: 3

Question 5

+3 marksNumerical answer
Show answer

Correct answer: 4

Question 6

+3 marksOne correct option

Which among the following functions are positive definite?

  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • B

Question 7

+4 marksOne correct option

Given the following information about a 4×24 \times 2 matrix AA:

  • The characteristic polynomial of ATAA^T A is (λ−48)(λ−12)(\lambda - 48)(\lambda - 12).
  • Eigenvectors of ATAA^T A corresponding to eigenvalues λ=48\lambda = 48, λ=12\lambda = 12 are q1=(1/21/2)q_1 = \begin{pmatrix} 1/\sqrt{2} \\ 1/\sqrt{2} \end{pmatrix} and q2=(1/2−1/2)q_2 = \begin{pmatrix} 1/\sqrt{2} \\ -1/\sqrt{2} \end{pmatrix}, respectively.
  • Aq1=(4/2−8/204/2)Aq_1 = \begin{pmatrix} 4/\sqrt{2} \\ -8/\sqrt{2} \\ 0 \\ 4/\sqrt{2} \end{pmatrix}, Aq2=(−2/204/22/2)Aq_2 = \begin{pmatrix} -2/\sqrt{2} \\ 0 \\ 4/\sqrt{2} \\ 2/\sqrt{2} \end{pmatrix}

What is the matrix AA?

  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • D

Question 8

+4 marksNumerical answer
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Correct answer: 3

Question 9

+4 marksNumerical answer
Show answer

Correct answer: 5.5 (accepted within ±0.2)

Question 10

+2 marksOne correct option

Anwer the given subquestions.

  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • A

Question 11

+3 marksOne correct option

Anwer the given subquestions.

  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • A

Question 12

+3 marksOne correct option

Anwer the given subquestions.

  1. A
  2. B
  3. C
  4. D
Show answer

Correct answer

  • B

Question 13

+2 marksNumerical answer

Anwer the given subquestions.

Show answer

Correct answer: 0.22 (accepted within ±0.02)