Open in App
Not now

Class 12 NCERT Solutions – Mathematics Part I – Chapter 4 Determinants – Exercise 4.1

• Last Updated : 04 Mar, 2021

Question 1.

Solution:

The determinant of a 2 x 2 matrix

Hence,

Question 2. (i)

Solution:

from trigonometric identities

Solution:

Question 3. If  show that

Solution:

LHS=>

Matrix,

Hence, determinant,

RHS=>

Determinant,

Now,

Hence, proved, LHS = RHS

Question 4. If  then show that |

Solution:

LHS=>

Matrix,

Hence, determinant,

RHS =>

Determinant,

Now,

Hence, proved, LHS = RHS

(i)

Solution:

Since the maximum number of zeroes are in the second row, we will expand the determinant along row 2.

Solution:

(iii)

Solution:

Note: This matrix is skew symmetric i.e.

For every skew symmetric matrix of “odd dimension”, the determinant vanishes i.e. determinant is zero.

(iv)

Solution:

Since the maximum number of zeroes are in the second row, we will expand the determinant along row 2.

Solution:

(i)

Solution:

Solving determinants on both sides,

(ii)

Solution:

Solving determinants on both sides

(A) 6        (B)  ±6        (C) -6        (D) 0

Solution:

Solving determinants on both sides

Hence, Option (B)

My Personal Notes arrow_drop_up
Related Articles