NCERT Solutions class 12 Mathematics I 4. Determinants Miscellaneous Exercise on Chapter - 4

Detailed NCERT Solutions for 12 Mathematics I 4. Determinants to simplify learning. Understand chapters clearly and practice with free solutions for better results.

NCERT Solutions class 12 Mathematics I 4. Determinants Miscellaneous Exercise on Chapter - 4

NCERT Solutions class 12 Mathematics I 4. Determinants Miscellaneous Exercise on Chapter - 4

Detailed NCERT Solutions for 12 Mathematics I 4. Determinants to simplify learning. Understand chapters clearly and practice with free solutions for better results.

12 Mathematics I Chapter 4. Determinants - Miscellaneous Exercise on Chapter - 4

Preparing for exams becomes easier with Miscellaneous Exercise on Chapter - 4. Whether you are studying for board exams or mid-term exams, 12 Mathematics I Chapter 4. Determinants solutions provide quick revising points, well-structured answers, and additional practice material to help you score better.

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4. Determinants

Miscellaneous Exercise on Chapter - 4


 

Ques.1. Prove that the determinant  is independent of  

Ans. Let 

Expanding along R1,

 

 

  =  =  which is independent of 

 

 

Ques.2. Without expanding the determinants, prove that: 

Ans. L.H.S. = 

Multiplying R1 by  R2 by  and R3 by  = 

 =  [Interchanging C1 and C3]

 =  [Interchanging C2 and C3]

Proved.

 

 

Ques.3. Evaluate:  

Ans. Let 

Expanding along R1,

=

= 1

 

 

Ques.4. If  and  are real numbers and  Show that either  or 

Ans. Given: 

  

 

Here,   Either 

 ……….(i)

Or 

  

  [Expanding along first row]

 

 

 

 

 

 

 

  and  and  

  and  and  ……….(ii)

hance, from eq. (i) and (ii), either  or 

 

 

Ques.5. Solve the equation:  

Ans. Given: 

  

 

Either 

  ……….(i)

Or 

  

 

 

 

But this is contrary as given that .

hance, from eq. (i),  is only the solution.

 

 

Ques.6. Prove that:  

Ans. L.H.S. = 

 

 =  

 =  = R.H.S.    Proved.

 

 

Ques.7. If  and B =  find  

Ans. Given:  and B = 

Since,   [Reversal law] ……….(i)

Now 

 = 

hance,  exists.

  and  and 

 adj. B =  = 

 

From eq. (i), 

 

 

 

Ques.8. Let A =  verify that:

(i)    

(ii)  

Ans. Given: Matrix A = 

 

  = 

Therefore,  exists.

  and 

and 

 adj. A =  = B (say)

  =            ………(i)

 

 = 

hance,  exists.

  and 

and 

 adj. B =  = 

 

 ….(ii)

Now to find  (say), where

C = 

C = 

C =  =  =

hance,  exists.

  and 

and 

 adj. A = 

 ……….(iii)

Again 

 = A (given)

(i) 

 = 

[From eq. (ii) and (iii)]

(ii) 

  = 

 

 

Ques.9. Evaluate:  

Ans. Let 

 

 

 

Ques.10. Evaluate:  

Ans. Let 

 

 =  = 

 

 

Ques.11.  

Ans. L.H.S. =  =  

=

 

Expanding along C3 

 = R.H.S.

 

 

Ques.12.  

Ans. L.H.S. = 

 (say) ……….(i)

Now 

 From eq. (i), L.H.S. =  ……….(ii)

Now 

 

Expanding along C1

 From eq. (i), L.H.S. = 

 = R.H.S.

 

Ques.13.  

Ans. L.H.S. = 

 

 

 = R.H.S.

 

Ques.14.  

Ans. L.H.S.

 

 = 1 = R.H.S.

 

 

Ques.15.  = 0

Ans. L.H.S. = 

 

 [ C2 and C3 have become identical]

= 0 = R.H.S

 

Ques.16. Solve the system of the following equations: (Using matrices):

 

Ans. Putting  and  in the given equations,

  

 the matrix form of given equations is  [AX= B]

Here,   A =  X =  and B = 

 

  exists and unique solution is  ……….(i)

Now     and 

and 

 adj. A =  = 

And 

 From eq. (i),

📘 Why Miscellaneous Exercise on Chapter - 4 are Important?

Miscellaneous Exercise on Chapter - 4 are created by experts to give step-by-step explanations. Around 60–70% of exam questions are based on NCERT concepts. Our 12 Mathematics I Chapter 4. Determinants solutions help you understand the core concepts and practice effectively.

✍️ Quick Revising Points as Notes in Page-1

Revision is the key to exam success. Our notes for 12 Mathematics I highlight important formulas, key definitions, and exam-ready points from Chapter 4. Determinants. These quick revision notes make last-minute preparation easy.

📚 NCERT Exercise Solutions

Every NCERT chapter ends with exercises, and solving them is crucial. Our Miscellaneous Exercise on Chapter - 4 include complete solutions for 12 Mathematics I Chapter 4. Determinants exercises. With step-by-step answers, you gain clarity and confidence to attempt similar exam questions.

📝 Additional Important Questions & Answers

To boost your preparation, we also provide additional important questions with answers. These are prepared from previous year board papers, sample papers, and important concepts of Chapter 4. Determinants. Practicing these ensures you are well-prepared for both board and mid-term exams.

🎯 Useful for Board & Mid-Term Exams

Our Miscellaneous Exercise on Chapter - 4 are useful for both board exams and mid-term exams. For 12 Mathematics I, we provide notes, exercises, and important Q&A so that you can revise smartly and write perfect answers in exams.

🌟 Final Words

In short, Miscellaneous Exercise on Chapter - 4 for 12 Mathematics I Chapter 4. Determinants are a complete study package. With quick revising points, NCERT exercises, and additional important questions, you can prepare effectively for exams. Make these solutions your study companion and excel in your academic journey.

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