1. Class 12
  2. Solutions of Sample Papers and Past Year Papers - for Class 12 Boards
  3. CBSE Class 12 Sample Paper for 2022 Boards (MCQ Based - for Term 1)
Check sibling questions

Question 35 - CBSE Class 12 Sample Paper for 2022 Boards (MCQ Based - for Term 1) - Solutions of Sample Papers and Past Year Papers - for Class 12 Boards

Last updated at Dec. 16, 2024 by Teachoo

If A is square matrix such that A 2 = A, then (I + A)³ – 7 A is equal to:

(a) A              (b) I + A

(c) I − A         (d) I

 

This question is inspired from Misc. 15 (MCQ) - Chapter 3 Class 12 - Matrices

Transcript

Question 35 If A is square matrix such that A2 = A, then (I + A)³ – 7 A is equal to: (a) A (b) I + A (c) I − A (d) I Given that A2 = A Finding (I + A)3 – 7A (I + A)3 – 7A Using (a + b)3 = a3 + b3 + 3a2b + 3ab2 = (I)3 + (A)3 + 3(I)2 A + 3(I)A2 – 7A = I + A3 + 3 I A + 3A2 I – 7A = I + A3 + 3A + 3A2 – 7A = I + A2 . A + 3A + 3A2 – 7A = I + A . A + 3A + 3A – 7A = I + A2 + 6A – 7A = I + A2 – A = I + A – A = I So, the correct answer is (D)
  1. Class 12
  2. Solutions of Sample Papers and Past Year Papers - for Class 12 Boards

    3. CBSE Class 12 Sample Paper for 2022 Boards (MCQ Based - for Term 1)

    CBSE Class 12 Sample Paper for 2021 Boards →
CBSE Class 12 Sample Paper for 2021 Boards →
Class 12
Solutions of Sample Papers and Past Year Papers - for Class 12 Boards

About the Author

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo