Question

15. Find the equation of the line joining the points (3, 1) and (9, 3) using determinants. ​

Answer 1

Answer:

x = 3y

Step-by-step explanation:

Let p(x,y) be any point on the line joining (3,1) and (9,3)

∣

∣

∣

∣

∣

∣

∣

∣

x

3

9

y

1

3

1

1

1

∣

∣

∣

∣

∣

∣

∣

∣

=0

R

2

⇒R

2

−R

1

; R

3

⇒R

3

−R

1

∣

∣

∣

∣

∣

∣

∣

∣

x

3−x

9−x

y

1−y

3−y

1

0

0

∣

∣

∣

∣

∣

∣

∣

∣

=0

⇒ 1[(3−x)(3−y)−(1−y)(9−x)]=0

⇒ 9−3y−3x+xy+x−9+9y−xy=0

⇒ 6y−2x=0

⇒ x=3y