If A is the identity matrix of order 3 and B is its transpose, then what is the value of the determinant of the matrix C = A + B?

This question was previously asked in
NDA 01/2022: Maths Previous Year paper (Held On 10 April 2022)
View all NDA Papers >
  1. 1
  2. 2
  3. 4
  4. 8

Answer (Detailed Solution Below)

Option 4 : 8
Free
NDA 01/2025: English Subject Test
30 Qs. 120 Marks 30 Mins

Detailed Solution

Download Solution PDF

Concept:

1). Transpose of a Matrix:

     The new matrix obtained by interchanging the rows and columns of the original matrix is called

     the transpose of the matrix.

     For example: ⇒ 

     It is denoted by A' or AT.
2). For the addition and subtraction of two matrices, the order of matrices should be equal.

Calculation:

Given:

and 

C = A + B

⇒ 

⇒ 

⇒ ∣C∣ = 2(4 - 0)

⇒ ∣C∣ = 8

∴ The determinant of matrix C is 8.

Latest NDA Updates

Last updated on Jun 18, 2025

->UPSC has extended the UPSC NDA 2 Registration Date till 20th June 2025.

-> A total of 406 vacancies have been announced for NDA 2 Exam 2025.

->The NDA exam date 2025 has been announced. The written examination will be held on 14th September 2025.

-> The selection process for the NDA exam includes a Written Exam and SSB Interview.

-> Candidates who get successful selection under UPSC NDA will get a salary range between Rs. 15,600 to Rs. 39,100. 

-> Candidates must go through the NDA previous year question paper. Attempting the NDA mock test is also essential. 

More Matrices Questions

Hot Links: teen patti real cash game happy teen patti teen patti game - 3patti poker teen patti gold download teen patti download apk