Show that the lines and intersect. Find their point of intersection.

Given: - Two lines equation: and


To find: - Intersection point


We have,



x = 3λ – 1, y = 5λ – 3 and z = 7λ – 5


So, the coordinates of a general point on this line are


(3λ – 1, 5λ – 3, 7λ – 5)


The equation of the 2nd line is



x = μ + 2, y = 3μ + 4 and z = 5μ + 6


So, the coordinates of a general point on this line are


(μ + 2, 3μ + 4, 5μ + 6)


If the lines intersect, then they must have a common point.


Therefore for some value of λ and μ, we have


3λ – 1 = μ + 2 , 5λ – 3 = 3μ + 4, and 7λ – 5 = 5μ + 6


……(i)


5λ – 3μ = 7 ……(ii)


and 7λ – 5μ = 11 ……(iii)


putting value of λ from eq i in eq ii, we get







Now putting value of μ in eq i, we get





As we can see by putting the value of λ and μ in eq iii, that it satisfy the equation.


Check


7λ – 5μ = 11




11 = 11


LHS = RHS ; Hence intersection point exists or line do intersects


We can find an intersecting point by putting values of μ or λ in any one general point equation


Thus,


Intersection point


3λ – 1, 5λ – 3, 7λ – 5




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