हिंदी

Write the Number of Vectors of Unit Length Perpendicular to Both the Vectors → a = 2 ^ I + ^ J + 2 ^ K and → B = ^ J + ^ K . - Mathematics

Advertisements
Advertisements

प्रश्न

Write the number of vectors of unit length perpendicular to both the vectors \[\vec{a} = 2 \hat{ i } + \hat{ j }  + 2 \hat{ k }  \text{ and }  \vec{b} = \hat{ j }  + \hat{ k } \] .

 
टिप्पणी लिखिए
Advertisements

उत्तर

Unit vectors perpendicular to \[\vec{a}\] and \[\vec{b}\]  are \[\pm \left( \frac{\vec{a} \times \vec{b}}{\left| \vec{a} \times \vec{b} \right|} \right)\] .

\[\vec{a} \times \vec{b} = \begin{vmatrix}\hat{ i }& \hat{ j }  & \hat{ k } \\ 2 & 1 & 2 \\ 0 & 1 & 1\end{vmatrix} = - \hat{ i }  - 2 \hat{ j } + 2 \hat{ k } \]
∴ Unit vectors perpendicular to \[\vec{a}\] and \[\vec{b}\]  are  \[\pm \frac{- \hat{ i } - 2 \hat{ j } + 2 \hat{ k } }{\sqrt{\left( - 1 \right)^2 + \left( - 2 \right)^2 + \left( 2 \right)^2}} = \pm \left( - \frac{1}{3} \hat{ i }  - \frac{2}{3} \hat{ j } + \frac{2}{3} \hat{ k } \right)\] 
Thus, there are two unit vectors perpendicular to the given vectors.
 
 
 
shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 25: Vector or Cross Product - very short answers [पृष्ठ ३४]

APPEARS IN

आरडी शर्मा Mathematics [English] Class 12
अध्याय 25 Vector or Cross Product
very short answers | Q 30 | पृष्ठ ३४

वीडियो ट्यूटोरियलVIEW ALL [2]

संबंधित प्रश्न

Find λ and μ if  `(2hati + 6hatj + 27hatk) xx (hati + lambdahatj + muhatk) = vec0`.


Let the vectors `veca, vecb, vecc` given as `a_1hati + a_2hatj + a_3hatk, b_1hati + b_2hatj + b_3hatk, c_1hati + c_2hatj + c_3hatk` Then show that = `veca xx (vecb+ vecc) = veca xx vecb + veca xx vecc.`


Let the vectors `veca` and `vecb` be such that `|veca| = 3` and `|vecb| = sqrt2/3`, then `veca xx vecb` is a unit vector, if the angle between `veca` and `vecb` is ______.


If θ is the angle between two vectors `hati - 2hatj + 3hatk and 3hati - 2hatj + hatk` find `sin theta`


Let `veca = 4hati + 5hatj - hatk`, `vecb  = hati - 4hatj + 5hatk` and `vecc = 3hati + hatj - hatk`. Find a vector `vecd` which is perpendicular to both `vecc` and `vecb and vecd.veca = 21`


If A, B, C are three non- collinear points with position vectors `vec a, vec b, vec c`, respectively, then show that the length of the perpendicular from Con AB is `|(vec a xx vec b)+(vec b xx vec c) + (vec b xx  vec a)|/|(vec b -  vec a)|`


If \[\vec{a} = 3 \hat { i } + 4 \hat { j } \text{ and }  \vec{b} = \hat { i  } + \hat{ j }  + \hat{ k } ,\]  find the value of \[\left| \vec{a} \times \vec{b} \right| .\]

 

 Find a unit vector perpendicular to both the vectors  \[4 \hat{ i } - \hat{ j }  + 3 \hat{ k } \text{ and }  - 2 \hat{ i  } + \hat{ j }  - 2 \hat{ k }  .\]

 


Find the magnitude of \[\vec{a} = \left( 3 \hat{ k }  + 4 \hat{ j } \right) \times \left( \hat{ i }  + \hat{ j }  - \hat{ k }  \right) .\]

 

\[\text{ If }  \vec{ a } = 3 \hat{ i }- \hat{ j }  - 2 \hat{ k } \text{  and } \vec{b} = 2 \hat{ i }  + 3 \hat{ j } + \hat{ k }  , \text{ find }  \left( \vec{a} + 2 \vec{b} \right) \times \left( 2 \vec{a} - \vec{b} \right) .\]

 


Find the area of the parallelogram determined by the vector \[2 \hat{ i } + \hat{ j } + 3 \hat{ k }  \text{ and }  \hat{ i }  - \hat{ j } \] .

 


Find the area of the parallelogram determined by the vector \[3 \hat{ i } + \hat{ j }  - 2 \hat{ k } \text{  and }  \hat{ i }  - 3 \hat{ j }  + 4 \hat{ k } \] .

 


Find the area of the parallelogram whose diagonals are  \[3 \hat{ i }  + 4 \hat{ j }  \text{ and } \hat{ i } + \hat{ j } + \hat{ k }\]

 


Find the area of the triangle formed by OAB when \[\vec{OA} = \hat{ i } + 2 \hat{ j }  + 3 \hat{ k }  , \vec{OB} = - 3 \hat{ i }  - 2 \hat{ j }+ \hat{ k }  .\]


Let \[\vec{a} = \hat{ i } + 4 \hat{ j }  + 2 \hat{ k } , \vec{b} = 3 \hat{ i }- 2 \hat{ j } + 7 \hat{ k }  \text{ and } \vec{c} = 2 \hat{ i } - \hat{ j }  + 4 \hat{ k }  .\]  Find a vector \[\vec{d}\] which is perpendicular to both \[\vec{a} \text{ and } \vec{d}\] \[\text{ and }  \vec{c} \cdot \vec{d} = 15 .\]

 
 

 


The two adjacent sides of a parallelogram are \[2 \hat{ i  } - 4 \hat{ j }  + 5 \hat{ k }  \text{ and }  \hat{ i } - 2 \hat{ j }  - 3\hat{ k }  .\]\  Find the unit vector parallel to one of its diagonals. Also, find its area. 

 
 

Find all vectors of magnitude \[10\sqrt{3}\] that are perpendicular to the plane of \[\hat{ i }  + 2 \hat{ j }  + \hat{ k } \] and \[- \hat { i }  + 3 \hat{ j }  + 4 \hat{ k } \] .

 

Define vector product of two vectors.

 

Write the value  \[\left( \hat{ i }  \times \hat{ j }  \right) \cdot \hat{ k }  + \hat{ i }  \cdot \hat{ j }  .\]

 


Write the value of \[\hat{ i }  × \left( \hat{ j } + \hat{ k }  \right) + \hat{ j }   ×  \left( \hat{ k } + \hat{ i }  \right) + \hat{ k }  ×   \left( \hat{ i }  + \hat{ j }  \right) .\]

 

If   \[\vec{a} \text{ and }  \vec{b}\] are two vectors such that \[\left| \vec{a} \times \vec{b} \right| = \sqrt{3}\text{ and }  \vec{a} . \vec{b} = 1,\]  find the angle between.

 
 

 


For any three vectors \[\vec{a,} \vec{b} \text{ and }  \vec{c}\] write the value of \[\vec{a} \times \left( \vec{b} + \vec{c} \right) + \vec{b} \times \left( \vec{c} + \vec{a} \right) + \vec{c} \times \left( \vec{a} + \vec{b} \right) .\]

 
 

For any two vectors \[\vec{a} \text{ and } \vec{b} , \text{ find } \left( \vec{a} \times \vec{b} \right) . \vec{b} .\]

 

Write a unit vector perpendicular to \[\hat{ i } + \hat{ j }  \text{ and }  \hat{ j }  + \hat{ k } .\]

 


If \[\vec{r} = x \hat{ i } + y \hat{ j }  + z \hat{ k }  ,\] then write the value of \[\left| \vec{r} \times \hat{ i }  \right|^2 .\]

 

 


If \[\vec{a}\] is a unit vector such that \[\vec{a} \times \hat{ i }  = \hat{ j }  , \text{ find }  \vec{a} . \hat{ i } \] .

 

Write the value of \[\left( \hat{ i }  \times \hat{ j }  \right) \cdot \hat{ k }  + \left( \hat{ j } + \hat{ k }  \right) \cdot \hat{ j } \]

 

Find a vector of magnitude \[\sqrt{171}\]  which is perpendicular to both of the vectors \[\vec{a} = \hat{ i } + 2 \hat{ j }  - 3 \hat{ k } \]  and  \[\vec{a} = \hat{ i } + 2 \hat{ j }  - 3 \hat{ k } \] . 

 
 

Write the angle between the vectors  \[\vec{a} \times \vec{b}\]  and  \[\vec{b} \times \vec{a}\] .

 

 


Vectors \[\vec{a} \text{ and }  \vec{b}\] are inclined at angle θ = 120°. If \[\left| \vec{a} \right| = 1, \left| \vec{b} \right| = 2,\] then  \[\left[ \left( \vec{a} + 3 \vec{b} \right) \times \left( 3 \vec{a} - \vec{b} \right) \right]^2\]  is equal to 

 
  

If \[\vec{a} = 2 \hat{ i }  - 3 \hat{ j }  - \hat{ k }  \text{ and }  \vec{b} = \hat{ i } + 4 \hat{ j }  - 2 \hat{ k 
} , \text{ then } \vec{a} \times \vec{b}\]  is


If θ is the angle between any two vectors `bara` and `barb` and `|bara · barb| = |bara xx barb|` then θ is equal to ______.


Let `veca, vecb, vecc` be three vectors mutually perpendicular to each other and have same magnitude. If a vector `vecr` satisfies. `veca xx {(vecr - vecb) xx veca} + vecb xx {(vecr - vecc) xx vecb} + vecc xx {(vecr - veca) xx vecc} = vec0`, then `vecr` is equal to ______.


If the angle between `veca` and `vecb` is `π/3` and `|veca xx vecb| = 3sqrt(3)`, then the value of `veca.vecb` is ______.


If `|veca xx vecb| = sqrt(3)` and `veca.vecb` = – 3, then angle between `veca` and `vecb` is ______.


Find the area of a parallelogram whose adjacent sides are determined by the vectors `veca = hati - hatj + 3hatk` and `vecb = 2hati - 7hatj + hatk`.


If `veca = hati + hatj + hatk` and `vecb = hati + 2hatj + 3hatk` then find a unit vector perpendicular to both `veca + vecb` and `veca - vecb`.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×