Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • School
  • Please solve RD Sharma class 12 chapter 4 Algebra of Matrices exercise Fill in the blank question 5 maths textbook solution

Please solve RD Sharma class 12 chapter 4 Algebra of Matrices exercise Fill in the blank question 5 maths textbook solution

Answers (1)

Answer:

x = 1

 Hint:

Use the basic concept of identity matrix.

Given:

A=\left[\begin{array}{cc} \frac{1}{3} & 2 \\ 0 & 2 x-3 \end{array}\right] \text { and } B=\left[\begin{array}{cc} 3 & 6 \\ 0 & -1 \end{array}\right],[A B]=[I]

Find x

 Solution:

\begin{aligned} &\text { Here, }[A B]=[I] \\ &\text { So, }\left[\begin{array}{cc} \frac{1}{3} & 2 \\ 0 & 2 x-3 \end{array}\right]\left[\begin{array}{cc} 3 & 6 \\ 0 & -1 \end{array}\right]=\left[\begin{array}{ll} 1 & 0 \\ 0 & 1 \end{array}\right] \\ &=\left[\begin{array}{ll} \frac{1}{3} \times 3+2 \times 0 & \frac{2}{3} \times 6+2 \times(-1) \\ 0 \times 3+0 \times 0 & 0+(2 x-3)(-1) \end{array}\right]=\left[\begin{array}{ll} 1 & 0 \\ 0 & 1 \end{array}\right] \end{aligned}

=\left[\begin{array}{cc} 1 & 0 \\ 0 & 2 x+3 \end{array}\right]=\left[\begin{array}{ll} 1 & 0 \\ 0 & 1 \end{array}\right]

So, here both sides have 2 x 2 matrices

Hence, by comparing respective elements,

\begin{aligned} &-2 s+3=1 \\ &3-1=2 x \\ &2=2 x \\ &x=1 \end{aligned}

Posted by

Gurleen Kaur

View full answer

Crack CUET with india's "Best Teachers"

  • HD Video Lectures
  • Unlimited Mock Tests
  • Faculty Support
cuet_ads

Similar Questions

Trending Articles/News

anam-khan

CBSE Class 12 board exams 2025 to have 50% competency-based questions; no change in 10th
anam-khan

CBSE Class 12 board exams 2024 over; expected result date, trends of last 10 years
anam-khan

CBSE Class 12 accountancy board exam analysis 2024 out; paper rated easy, balanced

Latest Question