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If vecaxxvecb=vecc and vecbxxvecc=veca t...

If `vecaxxvecb=vecc` and `vecbxxvecc=veca` then
a. `veca,vecb,vecc` are orthogonal in pairs and `|veca|=|vecc|,|vecb|=1`
b. `veca,vecb,vecc` are not orthogonal to each other
c. `veca,vecb,vecc` are orthogonal in pairs but `|veca|!=|vecc|`
d. `veca,vecb,vecc` are orthogonal but `|vecb|=1`
OR
If `vecaxxvecb=vecc,vecbxxvecc=veca`, then

A

`|veca|=1,vecb=vecc`

B

`|vecc|=1,|veca|=1`

C

`|vecb|=2,vecc=2veca`

D

`|vecb|=1,|vecc|=|veca|`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we have two equations involving three vectors \(\vec{a}\), \(\vec{b}\), and \(\vec{c}\): 1. \(\vec{a} \times \vec{b} = \vec{c}\) 2. \(\vec{b} \times \vec{c} = \vec{a}\) We need to analyze these equations to determine the relationships between the vectors. ### Step 1: Cross Product Properties Recall the properties of the cross product. For any vectors \(\vec{x}\), \(\vec{y}\), and \(\vec{z}\): - \(\vec{x} \times \vec{y}\) is orthogonal to both \(\vec{x}\) and \(\vec{y}\). - The magnitude of the cross product is given by \(|\vec{x} \times \vec{y}| = |\vec{x}||\vec{y}|\sin(\theta)\), where \(\theta\) is the angle between \(\vec{x}\) and \(\vec{y}\). ### Step 2: Analyze \(\vec{a} \times \vec{b} = \vec{c}\) From the first equation, \(\vec{c}\) is orthogonal to both \(\vec{a}\) and \(\vec{b}\). Therefore: - \(\vec{a} \cdot \vec{c} = 0\) - \(\vec{b} \cdot \vec{c} = 0\) ### Step 3: Analyze \(\vec{b} \times \vec{c} = \vec{a}\) From the second equation, \(\vec{a}\) is orthogonal to both \(\vec{b}\) and \(\vec{c}\). Therefore: - \(\vec{b} \cdot \vec{a} = 0\) - \(\vec{c} \cdot \vec{a} = 0\) ### Step 4: Magnitudes of the Vectors Next, we can find the magnitudes of the vectors. From the first equation: \[ |\vec{c}| = |\vec{a} \times \vec{b}| = |\vec{a}||\vec{b}|\sin(\theta) \] Since \(\vec{a}\) and \(\vec{b}\) are orthogonal, \(\theta = 90^\circ\) and \(\sin(90^\circ) = 1\): \[ |\vec{c}| = |\vec{a}||\vec{b}| \] From the second equation: \[ |\vec{a}| = |\vec{b} \times \vec{c}| = |\vec{b}||\vec{c}|\sin(\phi) \] Again, since \(\vec{b}\) and \(\vec{c}\) are orthogonal, \(\phi = 90^\circ\) and \(\sin(90^\circ) = 1\): \[ |\vec{a}| = |\vec{b}||\vec{c}| \] ### Step 5: Setting Up Equations Now we have two equations: 1. \( |\vec{c}| = |\vec{a}||\vec{b}| \) 2. \( |\vec{a}| = |\vec{b}||\vec{c}| \) Substituting \( |\vec{c}| \) from the first equation into the second: \[ |\vec{a}| = |\vec{b}| \cdot (|\vec{a}||\vec{b}|) \] This simplifies to: \[ |\vec{a}| = |\vec{a}||\vec{b}|^2 \] If \( |\vec{a}| \neq 0 \), we can divide both sides by \( |\vec{a}| \): \[ 1 = |\vec{b}|^2 \] Thus, we conclude that: \[ |\vec{b}| = 1 \] ### Step 6: Conclusion on Orthogonality Since all pairs of vectors are orthogonal, we conclude: - \(\vec{a}\), \(\vec{b}\), and \(\vec{c}\) are orthogonal to each other. - The magnitudes of \(\vec{a}\) and \(\vec{c}\) are equal. ### Final Answer Thus, the correct option is: **a. \(\vec{a}, \vec{b}, \vec{c}\) are orthogonal in pairs and \(|\vec{a}| = |\vec{c}|, |\vec{b}| = 1\)**.

To solve the problem, we have two equations involving three vectors \(\vec{a}\), \(\vec{b}\), and \(\vec{c}\): 1. \(\vec{a} \times \vec{b} = \vec{c}\) 2. \(\vec{b} \times \vec{c} = \vec{a}\) We need to analyze these equations to determine the relationships between the vectors. ### Step 1: Cross Product Properties ...
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OBJECTIVE RD SHARMA-SCALAR AND VECTOR PRODUCTS OF THREE VECTORS -Exercise
  1. If veca, vecb, vecc are non-coplanar unit vectors such that vecaxx(vec...

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  2. Let a,b,c be distinct non-negative numbers. If the vectors ahati+ahatj...

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  3. If vecaxxvecb=vecc and vecbxxvecc=veca then a. veca,vecb,vecc are ort...

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  4. If vecp=(vecbxxvecc)/([(veca,vecb,vecc)]),vecq=(veccxxveca)/([(veca,ve...

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  5. If vecrxxveca=vecbxxveca,vecrxxvecb=vecaxxvecb,veca!=0,vecb!=0,veca!=l...

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  6. The vector veca coplanar with the vectors hati and hatj perendicular t...

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  7. If the vectors veca and vecb are mutually perpendicular, then vecaxx{v...

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  8. [((vecaxxvecb)xx(vecbxxvecc),(vecbxxvecc)xx(veccxxveca),(veccxxveca)xx...

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  9. Let veca=hati-hatj,vecb=hatj-hatk, vecc=hatk-hati. If hatd is a unit v...

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  10. If the vectors (sec^(2)A)hati+hatj+hatk, hati+(sec^(2)B)hatj+hatk,hati...

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  11. hata and hatb are two mutually perpendicular unit vectors. If the vect...

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  12. If three concurrent edges of a parallelopiped of volume V represent ve...

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  13. If veca=hati+hatj+hatk, vecb=hati+hatj,vecc=hati and (vecaxxvecb)xxvec...

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  14. If veca=2hati-3hatj+5hatk , vecb=3hati-4hatj+5hatk and vecc=5hati-3hat...

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  15. If veca,vecb,vecc are linearly independent vectors, then ((veca+2vecb)...

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  16. If veca,vecb are non-collinear vectors, then [(veca,vecb,hati)]hati+[...

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  17. If [(2veca+4vecb,vecc,vecd)]=lamda[(veca,vecc,vecd)]+mu[(vecb,vecc,vec...

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  18. If the volume of the tetrahedron whose vertices are (1,-6,10),(-1,-3,7...

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  19. (vecbxxvecc)xx(veccxxveca)=

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  20. When a right handed rectangular Cartesian system OXYZ rotated about z-...

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