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 Determinants exercise 5.1 question 4 maths textbook solution

Please solve RD Sharma class 12 chapter Determinants exercise 5.1 question 4 maths textbook solution

Answers (1)

Answer:

D=1

Hint:

Determinant matrix must be square (i.e. same number of rows and columns)

Given:

\begin{aligned} \left|\begin{array}{cc} \sin 10^{\circ} & -\cos 10^{\circ} \\ \sin 80^{\circ} & \cos 80^{\circ} \end{array}\right|\\ \end{aligned}

Solution:

\begin{aligned} &\Delta=\mathrm{a}_{11} \mathrm{C}_{11}+\mathrm{a}_{21} \mathrm{C}_{21}\\ &=\sin 10^{\circ} \cos 80^{\circ}+\cos 10^{\circ} \sin 80^{\circ}\\ &=\sin 10^{\circ} \cos \left(90^{\circ}-10^{\circ}\right)+\cos 10^{\circ} \sin \left(90^{\circ}-10^{\circ}\right) \quad\quad\quad \quad\left[\sin \left(90^{\circ}-\theta\right)=\cos \theta\right]\\ &=\sin 10^{\circ} \sin 10^{\circ}+\cos 10^{\circ} \cos 10^{\circ}\\ &=\sin ^{2} 10^{\circ}+\cos ^{2} 10^{\circ} \quad \quad \quad \quad \quad\left[\cos ^{2} \theta+\sin ^{2} \theta=1\right]\\ &=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 2026 Admit Card LIVE: CBSE Class 10, 12 hall ticket soon at cbse.gov.in; direct link, datesheet, updates
anam-khan

CBSE 2026 Admit Card LIVE: CBSE Class 10, 12 hall tickets for private candidates declared at cbse.gov.in
anam-khan

Looking forward to interacting with students at Pariksha Pe Charcha 2026: PM Narendra Modi

Latest Question