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# NCERT Solutions - Determinants, Exercise 4.1 JEE Notes | EduRev

## Mathematics (Maths) Class 12

Created by: Tarun Kaushik

## JEE : NCERT Solutions - Determinants, Exercise 4.1 JEE Notes | EduRev

The document NCERT Solutions - Determinants, Exercise 4.1 JEE Notes | EduRev is a part of the JEE Course Mathematics (Maths) Class 12.
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Determinants

Exercise 4.1
Question 1: Evaluate the determinants in Exercises 1 and 2.  = 2(−1) − 4(−5) = − 2 + 20 = 18

Question 2: Evaluate the determinants in Exercises 1 and 2.  (i) = (cos θ)(cos θ) − (−sin θ)(sin θ) = cos2 θ+ sin2 θ = 1 (ii) = (x2 − x + 1)(x + 1) − (x − 1)(x + 1)
= x3 − x2 + x + x2 − x + 1 − (x2 − 1)
= x+ 1 − x2 + 1
= x− x2 + 2

Question 3:  .

Question 4: The given matrix is . Question 5: Evaluate the determinants (i) Let It can be observed that in the second row, two entries are zero. Thus, we expand along the second row for easier calculation.  Question 6:
If  Question 7: Find values of x, if  Question 8:
If , then x is equal to

(A) 6

(B) ±6

(C) −6

(D) 0 Hence, the correct answer is B.

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