Show that the lines $\frac{x-1}{2}=\frac{y-2}{3}=\frac{z-3}{4}$ and $\frac{x-4}{5}=\frac{y-1}{2}=\frac{z-0}{1}$ intersect. Also,find their point of intersection.

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(A) Let the equations of the lines be:
$L_1: \frac{x-1}{2}=\frac{y-2}{3}=\frac{z-3}{4} = \lambda$
$L_2: \frac{x-4}{5}=\frac{y-1}{2}=\frac{z-0}{1} = \mu$
Any point on $L_1$ is $(2\lambda+1, 3\lambda+2, 4\lambda+3)$ and any point on $L_2$ is $(5\mu+4, 2\mu+1, \mu)$.
If the lines intersect,there exist $\lambda$ and $\mu$ such that:
$2\lambda+1 = 5\mu+4 \Rightarrow 2\lambda - 5\mu = 3$ $(1)$
$3\lambda+2 = 2\mu+1 \Rightarrow 3\lambda - 2\mu = -1$ $(2)$
$4\lambda+3 = \mu$ $(3)$
Substitute $(3)$ into $(1)$:
$2\lambda - 5(4\lambda+3) = 3$
$2\lambda - 20\lambda - 15 = 3$
$-18\lambda = 18 \Rightarrow \lambda = -1$
Using $\lambda = -1$ in $(3)$:
$\mu = 4(-1)+3 = -1$
Check these values in $(2)$:
$3(-1) - 2(-1) = -3 + 2 = -1$. This satisfies equation $(2)$.
Since the values satisfy all equations,the lines intersect.
Point of intersection using $\lambda = -1$:
$x = 2(-1)+1 = -1$
$y = 3(-1)+2 = -1$
$z = 4(-1)+3 = -1$
Thus,the point of intersection is $(-1, -1, -1)$.

Explore More

Similar Questions

The foot of the perpendicular drawn from the point $(1, 8, 4)$ on the line joining the points $(0, -11, 4)$ and $(2, -3, 1)$ is

The lines $\frac{x - 1}{-1} = \frac{y + 2}{1} = \frac{z - 3}{-2}$ and $\frac{x - 1}{1} = \frac{y + 2}{1} = \frac{z + 1}{-2}$ are

The values of $p$ and $q$ such that the line joining the points $(7, p, 2)$ and $(q, -2, 5)$ is parallel to the line joining the points $(2, -3, 5)$ and $(-6, -15, 11)$ are:

The angle between the lines $x-3y-4=0, 4y-z+5=0$ and $x+3y-11=0, 2y-z+6=0$ is

The point of intersection of the two lines $\frac{x - 3}{3} = \frac{y - 3}{-1}, z - 1 = 0$ and $\frac{x - 6}{2} = \frac{z - 1}{3}, y - 2 = 0$ is

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo