Show that the lines and
are intersecting. Hence, find their point of intersection.
Given: – Two lines having vector notion and
To show: - Lines are intersecting
The position vectors of arbitrary points on the given lines are
1st line
2nd line
If the lines intersect, then they must have a common point.
Therefore for some value of λ and μ, we have
⇒ (λ + 3) = 3μ + 5, 2λ + 2 = 2μ – 2, 2λ – 4 = 6μ
⇒ λ = 3μ + 2 …… (i)
⇒ λ – μ = – 2 ……(ii)
and λ – 3μ = 2 ……(iii)
putting value of λ from eq i in eq ii, we get
⇒ λ – μ = – 2
⇒ 3μ + 2 – μ = – 2
⇒ 2μ = – 4
⇒ μ = – 2
Now putting value of μ in eq i, we get
⇒ λ = 3μ + 2
⇒ λ = 3( – 2) + 2
⇒ λ = – 6 + 2
⇒ λ = – 4
As we can see by putting value of λ and μ in eq iii, that it satisfy the equation.
Check
⇒ λ – 3μ = 2
⇒ – 4 – 3( – 2) = 2
⇒ – 4 + 6 = 2
⇒ 2 = 2
⇒ LHS = RHS ; Hence intersection point exists or line do intersect
We can find an intersecting point by putting values of μ or λ in any one general point equation
Thus,
Intersection point
⇒
⇒
⇒
Hence, Intersection point is ( – 1, – 6, – 12)