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^) - Mathematics

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

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 [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

 

Find the shortest distance between the lines

`bar r = (4 hat i - hat j) + lambda(hat i + 2 hat j - 3 hat k)`

and

`bar r = (hat i - hat j + 2 hat k) + mu(hat i + 4 hat j -5 hat k)`

where λ and μ are parameters

 

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.

`(x + 1)/7 = (y + 1)/(- 6) = (z + 1)/1` and `(x - 3)/1 = (y - 5)/(- 2) = (z - 7)/1`.


Find the shortest distance between the lines whose vector equations are `vecr = (hati + 2hatj + 3hatk) + lambda(hati - 3hatj + 2hatk)` and `vecr = 4hati + 5hatj + 6hatk + mu(2hati + 3hatj + 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 `(x+1)/7=(y+1)/(-6)=(z+1)/1 and (x-3)/1=(y-5)/(-2)=(z-7)/1`


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 

\[\frac{x + 1}{7} = \frac{y + 1}{- 6} = \frac{z + 1}{1} \text{ and } \frac{x - 3}{1} = \frac{y - 5}{- 2} = \frac{z - 7}{1} .\]
 

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.

Given that the fuel cost per hour is k times the square of the speed the train generates in km/h, the value of k is:


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 total cost of the train to travel 500 km at the most economical speed 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)`


Find the angle between the following pair of lines:- `(x - 2)/ = (y - 1)/5 = (z + 3)/(-3)` and `(x + 2)/(-1) = (y - 4)/8 = (z - 5)/4`


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)`


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


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


An insect is crawling along the line `barr = 6hati + 2hatj + 2hatk + λ(hati - 2hatj + 2hatk)` and another insect is crawling along the line `barr = - 4hati - hatk + μ(3hati - 2hatj - 2hatk)`. At what points on the lines should they reach so that the distance between them s the shortest? Find the shortest possible distance between them.


Find the shortest distance between the following lines:

`vecr = 3hati + 5hatj + 7hatk + λ(hati - 2hatj + hatk)` and `vecr = (-hati - hatj - hatk) + μ(7hati - 6hatj + hatk)`.


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 ______.


The shortest distance between the z-axis and the line x + y + 2z – 3 = 0 = 2x + 3y + 4z – 4, 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 ______.


An aeroplane is flying along the line `vecr = λ(hati - hatj + hatk)`; where 'λ' is a scalar and another aeroplane is flying along the line `vecr = hati - hatj + μ(-2hatj + hatk)`; where 'μ' is a scalar. At what points on the lines should they reach, so that the distance between them is the shortest? Find the shortest possible distance between them.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×