मराठी

Find the shortest distance between the lines: r→ =(i^+2j^+k^)+λ(i^-j^+k^) and r→=2i^-j^-k^+μ(2i^+j^+2k^)

Advertisements
Advertisements

प्रश्न

Find the shortest distance between the lines: 

`vecr = (hati+2hatj+hatk) + lambda(hati-hatj+hatk)` and `vecr = 2hati - hatj - hatk + mu(2hati + hatj + 2hatk)`

बेरीज
Advertisements

उत्तर

Given the equation of lines `vecr = (hati + 2hatj + hatk) + λ(hati - hatj + hatk)`       .....(1)

and `vecr = 2hati - hatj - hatk + µ(2hati + hatj + 2hatk)`     .....(2)

Comparing equation (1) with `vecr = vec(a_1) + λvec(b_1)` and equation (2) with `vecr = vec(a_2) + µvec(b_2)`,

`vec(a_1) = hati + 2hatj + hatk`  and  `vec(a_2) = 2hati - 2hatj - hatk` 

`vec(b_1) = hati - hatj + hatk`  and  `vec(b_2) = 2hati + hatj + 2hatk` 

Now, `vec(a_2) - vec(a_1) = hati - 3hatj - 2hatk`

and `vec(b_1) xx vec(b_2) = |(hati, hatj, hatk), (1, -1, 1), (2, 1, 2)|`

= `(-2 -1) hati - (2 - 2) hatj + (1 + 2) hatk`

= `-3hati - 0hatj + 3hatk`

Required shortest distance

`= |((vecb_1 xx vecb_2)* (veca_2 - veca_1))/|vecb_1 xx vecb_2||`

`= |((-3hati + 3hatk)* (hati - 3hatj - 2hatk))/|-3hati + 3hatk||`

`= |((-3) xx 1 + 0 xx (-3) + 3 xx (-2))/ sqrt((-3)^2 + 3^2)|`

`= 9/sqrt18`

`= 9/(3sqrt2)`

`= 3/sqrt2` units

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 11: Three Dimensional Geometry - Exercise 11.2 [पृष्ठ ४७८]

APPEARS IN

एनसीईआरटी Mathematics Part 1 and 2 [English] Class 12
पाठ 11 Three Dimensional Geometry
Exercise 11.2 | Q 14 | पृष्ठ ४७८

संबंधित प्रश्‍न

If the lines

`(x-1)/-3=(y-2)/(2k)=(z-3)/2 and (x-1)/(3k)=(y-5)/1=(z-6)/-5`

are at right angle then find the value of k

 

Show that the following two lines are coplanar:

`(x−a+d)/(α−δ)= (y−a)/α=(z−a−d)/(α+δ) and (x−b+c)/(β−γ)=(y−b)/β=(z−b−c)/(β+γ)`


Find the distance between the planes 2x - y +  2z = 5 and 5x - 2.5y + 5z = 20


Find the shortest distance between the lines whose vector equations are `vecr = (1-t)hati + (t - 2)hatj + (3 -2t)hatk` and `vecr = (s+1)hati + (2s + 1)hatk`.


Find the shortest distance between lines `vecr = 6hati + 2hatj + 2hatk + lambda(hati - 2hatj + 2hatk)` and `vecr =-4hati - hatk + mu(3hati - 2hatj - 2hatk)`.


Find the shortest distance between the lines `vec r = hat i + 2hat j + 3 hat k +  lambda(2 hat i +  3hatj +  4hatk)` and `vec r =  2hat i +  4 hat j + 5 hat k +  mu (4hat i + 6 hat j +  8 hat k)`


Find the shortest distance between the lines

\[\frac{x - 2}{- 1} = \frac{y - 5}{2} = \frac{z - 0}{3} \text{ and }  \frac{x - 0}{2} = \frac{y + 1}{- 1} = \frac{z - 1}{2} .\]
 

Find the shortest distance between the lines given by `vec"r" = (8 + 3lambdahat"i" - (9 + 16lambda)hat"j" + (10 + 7lambda)hat"k"` and `vec"r" = 15hat"i" + 29hat"j" + 5hat"k" + mu(3hat"i" + 8hat"j" - 5hat"k")`


The fuel cost per hour for running a train is proportional to the square of the speed it generates in km per hour. If the fuel costs ₹ 48 per hour at a speed of 16 km per hour and the fixed charges to run the train amount to ₹ 1200 per hour. Assume the speed of the train as v km/h.

The most economical speed to run the train is:


Find the shortest distance between the following lines:

`vecr = (hati + hatj - hatk) + s(2hati + hatj + hatk)`

`vecr = (hati + hatj - 2hatk) + t(4hati + 2hatj + 2hatk)`


What will be the shortest distance between the lines, `vecr = (hati + 2hatj + hatk) + lambda(hati - hatj + hatk)` and `vecr = (2hati - hatj - hatk) + mu(2hati + hatj + 2hatk)`


Distance between the planes :- 

`2x + 3y + 4z = 4` and `4x + 6y + 8z = 12` is


The planes `2x - y + 4z` = 5 and `5x - 2.5y + 10z` = 6


Read the following passage and answer the questions given below.

Two motorcycles A and B are running at the speed more than the allowed speed on the roads represented by the lines `vecr = λ(hati + 2hatj - hatk)` and `vecr = (3hati + 3hatj) + μ(2hati + hatj + hatk)` respectively.

Based on the above information, answer the following questions:

  1. Find the shortest distance between the given lines.
  2. Find the point at which the motorcycles may collide.

If the shortest distance between the lines `vecr_1 = αhati + 2hatj + 2hatk + λ(hati - 2hatj + 2hatk)`, λ∈R, α > 0 `vecr_2 = - 4hati - hatk + μ(3hati - 2hatj - 2hatk)`, μ∈R is 9, then α is equal to ______.


The shortest distance between the line y = x and the curve y2 = x – 2 is ______.


The largest value of a, for which the perpendicular distance of the plane containing the lines `vec"r" = (hat"i" + hat"j") + λ(hat"i" + "a"hat"j" - hat"k")` and `vec"r" = (hat"i" + hat"j") + μ(-hat"i" + hat"j" - "a"hat"k")` from the point (2, 1, 4) is `sqrt(3)`, is ______.


If the shortest distance between the lines `(x - 1)/2 = (y - 2)/3 = (z - 3)/λ` and `(x - 2)/1 = (y - 4)/4 = (z - 5)/5` is `1/sqrt(3)`, then the sum of all possible values of λ is ______.


Find the distance between the lines:

`vecr = (hati + 2hatj - 4hatk) + λ(2hati + 3hatj + 6hatk)`;

`vecr = (3hati + 3hatj - 5hatk) + μ(4hati + 6hatj + 12hatk)`


The lines `vecr = hati + hatj - hatk + λ(2hati + 3hatj - 6hatk)` and `vecr = 2hati - hatj - hatk + μ(6hati + 9hatj - 18hatk)`; (where λ and μ are scalars) are ______.


Show that the line whose vector equation is `vecr = (2hati - 2hatj + 3hatk) + λ(hati - hatj + 4hatk)` is parallel to the plane whose vector equation is `vecr.(hati + 5hatj + hatk) = 5`. Also find the distance between them.


What does the concept of shortest distance help in finding when two lines do not meet directly?


Given \[\vec r=\vec a_1+\lambda\vec b_1\] and \[\vec r=\vec a_2+\mu\vec b_2\], what are \[\vec b_1\] and \[\vec b_2\]?


For the Cartesian form of the distance between skew lines, which determinant is the numerator?


For \[\vec b_1=2\hat i-\hat j+\hat k\] and \[\vec b_2=3\hat i-5\hat j+2\hat k\], what is \[\vec b_1\times\vec b_2\]?


What is the distance between \[\vec r=(\hat i+\hat j)+\lambda(2\hat i-\hat j+\hat k)\] and \[\vec r=(2\hat i+\hat j-\hat k)+\mu(3\hat i-5\hat j+2\hat k)\]?


What is \[SD\] for intersecting lines?


For skew lines, which expression gives \[SD\]?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×