Question 1
Let the vectors be orthogonal. Which of the following must be true?
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The IIT Madras BS Machine Learning Foundations (MLF) Quiz 1 paper sat on 15 Mar 2026, in the January 2026 term: 18 questions for 42 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.
Let the vectors be orthogonal. Which of the following must be true?
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Correct answer
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Consider the function :
Which of the following is true?
is continuous at , but not differentiable at .
is both continuous and differentiable at .
is neither continuous nor differentiable at .
is differentiable at , but not continuous at .
Correct answer
is continuous at , but not differentiable at .
Consider the following matrices:
Which of the following is true?
is diagonalizable, is not diagonalizable.
is not diagonalizable, is diagonalizable.
Both and are diagonalizable.
Neither nor is diagonalizable
Correct answer
is not diagonalizable, is diagonalizable.
Consider a dataset for a regression problem where each element is of the form , for . is the feature and is the label of the data-point. Let be two regression models such that: Which of the following options is correct?
has the lower mean squared loss.
has the lower mean squared loss.
Both models have same mean squared loss.
Correct answer
has the lower mean squared loss.
Which of the following is a basis for the column space of the matrix given below?
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Correct answer
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The matrix
has eigenvalues and . Which of the following options is/are correct?
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Correct answers
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Which of the following is/are true?
If and are matrices of the same size, then .
The rank of a matrix is equal to the number of non-zero rows in it.
If is a matrix which is obtained by permuting the rows of the identity matrix, then the rank of is .
If is a non-zero column vector in , then the rank of the matrix is .
Correct answers
If is a matrix which is obtained by permuting the rows of the identity matrix, then the rank of is .
If is a non-zero column vector in , then the rank of the matrix is .
Let and be two lines in defined in parametric form:
For example, every point on line is of the form . Which of the following is/are true?
and are parallel
and are not parallel
and intersect at a point
and do not intersect at any point
Correct answers
and are not parallel
and do not intersect at any point
Which of the following is/are true ?
Every square matrix with real entries has at least one real eigenvalue.
A set of two eigenvectors corresponding to the same eigenvalue of a square matrix must be linearly dependent.
Given a square matrix of order , the set of all eigenvectors for an eigenvalue , along with the zero vector, forms a subspace of .
A square matrix is not invertible if and only if is one of its eigenvalues.
Correct answers
Given a square matrix of order , the set of all eigenvectors for an eigenvalue , along with the zero vector, forms a subspace of .
A square matrix is not invertible if and only if is one of its eigenvalues.
Suppose you are building a credit card fraud detection system and have two approaches: (i) Manually writing rules such as "If transaction amount is above Rs. 50,000 and the location is overseas, mark it as fraud.” (ii) Training a model using millions of past transactions labeled as fraud or not fraud. Which of the following options is/are correct?
Approach (i) is not machine learning.
Approach (ii) is machine learning.
Both approaches are machine learning.
Neither approach is machine learning.
Correct answers
Approach (i) is not machine learning.
Approach (ii) is machine learning.
Consider the function given by
. If the best linear approximation to at is given as , find . Your answer should be an integer.
A written answer, not marked automatically.
Find the directional derivative of the function given by at the point in the direction of the vector
. Your answer should be an integer.
A written answer, not marked automatically.
Let
be the projection matrix that projects vectors in onto the line . Let
be the matrix that projects vectors in onto the nullspace of . Based on the above data, answer the given subquestions.
Find . Your answer should be an integer.
A written answer, not marked automatically.
Let
be the projection matrix that projects vectors in onto the line . Let
be the matrix that projects vectors in onto the nullspace of . Based on the above data, answer the given subquestions.
Find . Your answer should be an integer.
A written answer, not marked automatically.
Consider the matrix given below:
Based on the above data, answer the given subquestions.
If is the smallest eigenvalue of , enter the value of . Your answer should be an integer.
A written answer, not marked automatically.
Consider the matrix given below:
Based on the above data, answer the given subquestions.
If is an eigenvector of corresponding to , find . Enter your answer correct to two decimal places.
A written answer, not marked automatically.
Let
be the projection matrix that projects vectors in onto the line . Let
be the matrix that projects vectors in onto the nullspace of . Based on the above data, answer the given subquestions.
A written answer, not marked automatically.
Consider the matrix given below:
Based on the above data, answer the given subquestions.
A written answer, not marked automatically.