Home
Class 12
MATHS
If veca, vecb, vecc are non-coplanar non...

If `veca, vecb, vecc` are non-coplanar non-zero vectors, then
`(vecaxxvecb)xx(vecaxxvecc)+(vecbxxvecc)xx(vecbxxveca)+(veccxxveca)xx(veccxxvecb)` is equal to

A

`[(veca, vecb, vecc)]^(2)(veca+vecb+vecc)`

B

`[(veca, vecb, vecc)](veca+vecb+vecc)`

C

`vec0`

D

none of these

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to evaluate the expression: \[ (\vec{a} \times \vec{b}) \times (\vec{a} \times \vec{c}) + (\vec{b} \times \vec{c}) \times (\vec{b} \times \vec{a}) + (\vec{c} \times \vec{a}) \times (\vec{c} \times \vec{b}) \] where \(\vec{a}, \vec{b}, \vec{c}\) are non-coplanar non-zero vectors. ### Step 1: Evaluate the first term Using the vector triple product identity: \[ \vec{p} \times (\vec{q} \times \vec{r}) = (\vec{p} \cdot \vec{r}) \vec{q} - (\vec{p} \cdot \vec{q}) \vec{r} \] Let \(\vec{p} = \vec{a}\), \(\vec{q} = \vec{b}\), and \(\vec{r} = \vec{c}\). Then we have: \[ (\vec{a} \times \vec{b}) \times (\vec{a} \times \vec{c}) = (\vec{a} \cdot \vec{c}) \vec{b} - (\vec{a} \cdot \vec{b}) \vec{c} \] ### Step 2: Evaluate the second term Using the same identity for the second term: \[ (\vec{b} \times \vec{c}) \times (\vec{b} \times \vec{a}) = (\vec{b} \cdot \vec{a}) \vec{c} - (\vec{b} \cdot \vec{c}) \vec{a} \] ### Step 3: Evaluate the third term Using the identity for the third term: \[ (\vec{c} \times \vec{a}) \times (\vec{c} \times \vec{b}) = (\vec{c} \cdot \vec{b}) \vec{a} - (\vec{c} \cdot \vec{a}) \vec{b} \] ### Step 4: Combine all terms Now we combine all three results: \[ [(\vec{a} \cdot \vec{c}) \vec{b} - (\vec{a} \cdot \vec{b}) \vec{c}] + [(\vec{b} \cdot \vec{a}) \vec{c} - (\vec{b} \cdot \vec{c}) \vec{a}] + [(\vec{c} \cdot \vec{b}) \vec{a} - (\vec{c} \cdot \vec{a}) \vec{b}] \] Grouping like terms, we have: \[ (\vec{a} \cdot \vec{c}) \vec{b} + (\vec{b} \cdot \vec{a}) \vec{c} + (\vec{c} \cdot \vec{b}) \vec{a} - [(\vec{a} \cdot \vec{b}) \vec{c} + (\vec{b} \cdot \vec{c}) \vec{a} + (\vec{c} \cdot \vec{a}) \vec{b}] \] ### Step 5: Recognizing the result Notice that the terms can be rearranged and factored as: \[ \vec{a} \cdot \vec{b} \cdot \vec{c} \text{ (as a scalar triple product)} \] Thus, the entire expression simplifies to: \[ \vec{a} \cdot \vec{b} \cdot \vec{c} \] ### Final Result The final result is: \[ \vec{a} \cdot \vec{b} \cdot \vec{c} \]

To solve the problem, we need to evaluate the expression: \[ (\vec{a} \times \vec{b}) \times (\vec{a} \times \vec{c}) + (\vec{b} \times \vec{c}) \times (\vec{b} \times \vec{a}) + (\vec{c} \times \vec{a}) \times (\vec{c} \times \vec{b}) \] where \(\vec{a}, \vec{b}, \vec{c}\) are non-coplanar non-zero vectors. ...
Promotional Banner

Topper's Solved these Questions

  • SCALAR AND VECTOR PRODUCTS OF THREE VECTORS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Section II - Assertion Reason Type|12 Videos
  • SCALAR AND VECTOR PRODUCTS OF THREE VECTORS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Exercise|63 Videos
  • SCALAR AND VECTOR PRODUCTS OF THREE VECTORS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Exercise|63 Videos
  • REAL FUNCTIONS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Chapter Test|58 Videos
  • SCALER AND VECTOR PRODUCTS OF TWO VECTORS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Section I - Solved Mcqs|12 Videos

Similar Questions

Explore conceptually related problems

If veca, vecb, vecc are three non coplanar, non zero vectors then (veca.veca)(vecbxxvecc)+(veca.vecb)(veccxxveca)+(veca.vecc)(vecaxxvecb) is equal to

If veca, vecb, vecc are any three non coplanar vectors, then (veca+vecb+vecc).(vecb+vecc)xx(vecc+veca)

If veca, vecba and vecc are non- coplanar vecotrs, then prove that |(veca.vecd)(vecbxxvecc)+(vecb.vecd)(veccxxveca)+(vecc.vecd)(vecaxxvecb) is independent of vecd where vecd is a unit vector.

If veca,vecb and vecc are three non coplanar vectors and vecr is any vector in space, then (vecaxxvecb)xx(vecrxxvecc)+(vecb xxvecc)xx(vecrxxveca)+(veccxxveca)xx(vecrxxvecb)=

If veca,vecb and vecc are three non coplanar vectors and vecr is any vector in space, then (vecaxxvecb),(vecrxxvecc)+(vecb xxvecc)xx(vecrxxveca)+(veccxxveca)xx(vecrxxvecb)=

If veca, vecb and vecc are three non-coplanar non-zero vectors, then prove that (veca.veca) vecb xx vecc + (veca.vecb) vecc xx veca + (veca.vecc)veca xx vecb = [vecb vecc veca] veca

If veca, vecb are non zero vectors, then ((vecaxxvecb)xxveca).((vecbxxveca)xxvecb) equals

If veca,vecb and vecc are three non coplanar vectors and vecr is any vector in space, then (vecxxvecb),(vecrxxvecc)+(vecb xxvecc)xx(vecrxxveca)+(veccxxveca)xx(vecrxxvecb)= (A) [veca vecb vecc] (B) 2[veca vecb vecc]vecr (C) 3[veca vecb vecc]vecr (D) 4[veca vecb vecc]vecr

If veca,vecb and vecc are three non coplanar vectors and vecr is any vector in space, then (vecxxvecb),(vecrxxvecc)+(vecb xxvecc)xx(vecrxxveca)+(veccxxveca)xx(vecrxxvecb)= (A) [veca vecb vecc] (B) 2[veca vecb vecc]vecr (C) 3[veca vecb vecc]vecr (D) 4[veca vecb vecc]vecr

If vecA, vecB, vecC are non-coplanar vectors then (vecA.vecBxxvecC)/(vecCxxvecA.vecB)+(vecB.vecAxxvecC)/(vecC.vecAxxvecB)=

OBJECTIVE RD SHARMA ENGLISH-SCALAR AND VECTOR PRODUCTS OF THREE VECTORS -Section I - Solved Mcqs
  1. Let veca, vecb and vecc be three having magnitude 1,1 and 2 respective...

    Text Solution

    |

  2. If veca = (hati + hatj +hatk), veca. vecb= 1 and vecaxxvecb = hatj -ha...

    Text Solution

    |

  3. If veca, vecb, vecc are non-coplanar non-zero vectors, then (vecaxxv...

    Text Solution

    |

  4. If the vectors veca, vecb, vecc and vecd are coplanar vectors, then (...

    Text Solution

    |

  5. (vecaxxvecb).(veccxxvecd) is not equal to

    Text Solution

    |

  6. Let veca = 2hati + hatj + hatk, and vecb = hati+ hatj if c is a vecto...

    Text Solution

    |

  7. If veca,vecb and vecc are three non coplanar vectors and vecr is any v...

    Text Solution

    |

  8. The number of faces of a triangular pyramid or tetrahedron is .

    Text Solution

    |

  9. The acute angle that the vector 2hati-2hatj+hatk makes with the plane ...

    Text Solution

    |

  10. If veca, vecb, vecc are non-null non coplanar vectors, then [(veca-2...

    Text Solution

    |

  11. The three vectors hat i+hat j,hat j+hat k, hat k+hat i taken two at a ...

    Text Solution

    |

  12. Let G(1), G(2) and G(3) be the centroid of the triangular faces OBC, O...

    Text Solution

    |

  13. Let vecr, veca, vecb and vecc be four non -zero vectors such that vecr...

    Text Solution

    |

  14. Let vecV = 2hati +hatj - hatk and vecW= hati + 3hatk . if vecU is a u...

    Text Solution

    |

  15. If a and b are unit vectors, then the vector defined as V=(a+b)times(a...

    Text Solution

    |

  16. If vec(alpha)=2hati+3hatj-hatk, vec(beta)=-hati+2hatj-4hatk, vecgamma=...

    Text Solution

    |

  17. Let alpha = a hati + b hatj + chatk , vecbeta = bhati + chatj + ahatk ...

    Text Solution

    |

  18. Given |veca|=|vecb|=1 and |veca + vecb|= sqrt3 if vecc is a vector suc...

    Text Solution

    |

  19. If vecmu and vecv be unit vector. If vecv is a vector such that vecv +...

    Text Solution

    |

  20. If veca, vecb, vecc be three vectors of magnitude sqrt(3),1,2 such tha...

    Text Solution

    |