## NCERT Solutions for Class 12 Maths Chapter 4 Exercise 4.3 (Ex 4.3)

Free PDF download of NCERT Solutions for Class 12 Maths Chapter 4 Exercise 4.3 (Ex 4.3) and all chapter exercises at one place prepared by expert teacher as per NCERT (CBSE) books guidelines. Class 12 Maths Chapter 4 Determinants Exercise 4.3 Questions with Solutions to help you to revise complete Syllabus and Score More marks.

## NCERT Solutions class 12 Maths Determinants

**1. Find the area of the triangle with vertices at the points given in each of the following:**

**(i) (1, 0), (6, 0), (4, 3)**

**(ii) (2, 7), (1, 1), (10, 8)**

**(iii) **** **

**Ans. (i) **Area of triangle = Modulus of =

= = = = sq. units

**(ii) **Area of triangle = Modulus of =

= =

= =

= = sq. units

**(iii) **Area of triangle = Modulus of =

=

=

=

=

= = 15 sq. units

### NCERT Solutions class 12 Maths Exercise 4.3

**2. Show that the points A**** B**** C**** are collinear.**

**Ans.** Area of triangle ABC = Modulus of =

=

=

=

= = 0

Therefore, points A, B and C are collinear.

### NCERT Solutions class 12 Maths Exercise 4.3

**3. Find values of **** if area of triangle is 4 sq. units and vertices are:**

**(i) **** **

**(ii) **** **

**Ans. (i) **Given: Area of triangle = Modulus of = 4

Modulus of = 4

Taking positive sign,

Taking negative sign,

**(ii)** Given: Area of triangle = Modulus of = 4

= 4

Taking positive sign,

Taking negative sign,

### NCERT Solutions class 12 Maths Exercise 4.3

**4. (i) Find the equation of the line joining (1, 2) and (3, 6) using determinants.**

**(ii) Find the equation of the line joining (3, 1) and (9, 3) using determinants.**

**Ans. (i) **Let P be any point on the line joining the points (1, 2) and (3, 6).

Then, Area of triangle that could be formed by these points is zero.

Area of triangle = Modulus of = 0

Modulus of = 0

which is required line.

**(ii) **Let P be any point on the line joining the points (3, 1) and (9, 3).

Then, Area of triangle that could be formed by these points is zero.

Area of triangle = Modulus of = 0

Modulus of = 0

which is required line.

### NCERT Solutions class 12 Maths Exercise 4.3

**5. If area of triangle is 35 sq. units with vertices **** and **** Then **** is:**

**(A) 12**

**(B) **** **

**(C) **** **

**(D) **** **

**Ans. **Given: Area of triangle = Modulus of = 35

Modulus of = 35

Taking positive sign,

Taking negative sign,

Therefore, option (D) is correct.

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