English
Tamil Nadu Board of Secondary EducationHSC Science Class 11

Find the direction cosines and direction ratios for the following vector ijk5i^-3j^-48k^

Advertisements
Advertisements

Question

Find the direction cosines and direction ratios for the following vector

`5hat"i" - 3hat"j" - 48hat"k"`

Sum
Advertisements

Solution

The direction ratios of the vector `5hat"i" - 3hat"j" - 48hat"k"` are (5, – 3, – 48)

The direction cosines of the vector `5hat"i" - 3hat"j" - 48hat"k"` are

`5/sqrt(5^2 + (-3)^2 + (-48)^2), (-3)/sqrt(5^2 + (-3)^2 + (-48)^2), (-48)/sqrt(5^2 + (-3)^2 + (-48)^2)`

`5/sqrt(25 + 9 + 2304), (-3)/sqrt(25 + 9 + 2304), (-48)/sqrt(25 + 9 + 2304)`

`(5/sqrt(2338), (-3)/sqrt(2338), (-4)/sqrt(2338))`

Direction ratios = (5, – 3, – 48)

Direction cosies = `(5/sqrt(2338), (-3)/sqrt(2338), (-4)/sqrt(2338))`

shaalaa.com
  Is there an error in this question or solution?
Chapter 8: Vector Algebra - Exercise 8.2 [Page 68]

APPEARS IN

Samacheer Kalvi Mathematics - Volume 1 and 2 [English] Class 11 TN Board
Chapter 8 Vector Algebra
Exercise 8.2 | Q 3. (iv) | Page 68

RELATED QUESTIONS

Find the direction cosines of the line perpendicular to the lines whose direction ratios are -2, 1,-1 and -3, - 4, 1 


Which of the following represents direction cosines of the line :

(a)`0,1/sqrt2,1/2`

(b)`0,-sqrt3/2,1/sqrt2`

(c)`0,sqrt3/2,1/2`

(d)`1/2,1/2,1/2`


If the lines `(x-1)/(-3) = (y -2)/(2k) = (z-3)/2 and (x-1)/(3k) = (y-1)/1 = (z -6)/(-5)` are perpendicular, find the value of k.


Show that the line through points (4, 7, 8) and (2, 3, 4) is parallel to the line through the points (−1, −2, 1) and (1, 2, 5).


Find the angle between the lines whose direction ratios are proportional to abc and b − cc − aa− b.


Write the distances of the point (7, −2, 3) from XYYZ and XZ-planes.


Write the ratio in which YZ-plane divides the segment joining P (−2, 5, 9) and Q (3, −2, 4).


A line makes an angle of 60° with each of X-axis and Y-axis. Find the acute angle made by the line with Z-axis.


Write the coordinates of the projection of the point P (2, −3, 5) on Y-axis.


Find the distance of the point (2, 3, 4) from the x-axis.


If a line makes angles 90° and 60° respectively with the positive directions of x and y axes, find the angle which it makes with the positive direction of z-axis.


For every point P (xyz) on the x-axis (except the origin),


If a line makes angles α, β, γ, δ with four diagonals of a cube, then cos2 α + cos2 β + cos2γ + cos2 δ is equal to


If a line makes angles 90°, 135°, 45° with the x, y and z axes respectively, find its direction cosines.


The vector equation of the line passing through the points (3, 5, 4) and (5, 8, 11) is `vec"r" = 3hat"i" + 5hat"j" + 4hat"k" + lambda(2hat"i" + 3hat"j" + 7hat"k")`


The line `vec"r" = 2hat"i" - 3hat"j" - hat"k" + lambda(hat"i" - hat"j" + 2hat"k")` lies in the plane `vec"r".(3hat"i" + hat"j" - hat"k") + 2` = 0.


If two straight lines whose direction cosines are given by the relations l + m – n = 0, 3l2 + m2 + cnl = 0 are parallel, then the positive value of c is ______.


A line in the 3-dimensional space makes an angle θ `(0 < θ ≤ π/2)` with both the x and y axes. Then the set of all values of θ is the interval ______.


If \[\alpha\], \[\beta\], and \[\gamma\] are the direction angles of a line, which ordered triple gives its direction cosines?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×