Home
Class 12
MATHS
Show by a numerical example and geomet...

Show by a numerical example and geometrically also that ` vec axx vec b= vec axx vec c` does not imply ` vec b= vec c `.

Text Solution

Verified by Experts

`Let veca= 3hati+2hatj+5hatk,hatb=6hati+5hatj+8hatk,vecc=3hati+3hatj+3hatk`
`vecaxxvecb=|{:(hati,hatj,hatk),(3,2,5),(6,5,8):}|`
`= (16-25) hati(24-30)hatj+(15-12)hatk`
`=-9hati+6hatj+3hatk`
`vecaxxvecc=|{:(hati,hatj,hatk),(3,2,5),(3,3,3):}|`
`= ( 6-15) hati-(9-15)hathj+ (9-6)hatk=-9hati+6hatj+3hatk`
`vecaxxvecb=vecaxxvecc ,but vecbnevecc`.
Promotional Banner

Topper's Solved these Questions

  • DIFFERENT PRODUCTS OF VECTORS AND THEIR GEOMETRICAL APPLICATIONS

    CENGAGE|Exercise Exercise|337 Videos
  • DETERMINANTS

    CENGAGE|Exercise All Questions|268 Videos
  • DIFFERENTIAL EQUATIONS

    CENGAGE|Exercise Question Bank|7 Videos

Similar Questions

Explore conceptually related problems

Show that ( vec a- vec b)xx( vec a+ vec b)=2( vec axx vec b)dot

If vec a , vec b , vec ca n d vec d are distinct vectors such that vec axx vec c= vec bxx vec da n d vec axx vec b= vec cxx vec d , prove that ( vec a- vec d)dot (vec b- vec c)!=0,

Let vec a , vec b ,a n d vec c be any three vectors, then prove that [ vec axx vec b vec bxx vec c vec cxx vec a]=[ vec a vec b vec c]^2dot

If vectors vec a , vec b ,a n d vec c are coplanar, show that | vec a vec b vec c vec adot vec a vec adot vec b vec adot vec c vec bdot vec a vec bdot vec b vec bdot vec c|=0

Given that vec adot vec b= vec adot vec c , vec axx vec b= vec axx vec ca n d vec a is not a zero vector. Show that vec b= vec cdot

If vec a and vec b are two vectors such that | vec axx vec b|=2, then find the value of [ vec a vec b vec axx vec b].

If vec ba n d vec c are two-noncollinear vectors such that vec a||( vec bxx vec c), then prove that ( vec axx vec b) . ( vec axx vec c) is equal to | vec a|^2( vec bdot vec c)dot

If vec a , vec b ,a n d vec c are three vectors such that vec axx vec b= vec c , vec bxx vec c= vec a , vec cxx vec a= vec b , then prove that | vec a|=| vec b|=| vec c|dot

If vec aa n d vec b are two vectors, then prove that ( vec axx vec b)^2=| vec adot vec a vec adot vec b vec bdot vec a vec bdot vec b| .

If vec aa n d vec b are two unit vectors incline at angle pi//3 , then { vec axx( vec b+ vec axx vec b)}dot vec b is equal to a. (-3)/4 b. 1/4 c. 3/4 d. 1/2

CENGAGE-DIFFERENT PRODUCTS OF VECTORS AND THEIR GEOMETRICAL APPLICATIONS -Exercise
  1. Show by a numerical example and geometrically also that vec axx vec...

    Text Solution

    |

  2. Find |veca|and|vecb|, if (veca+vecb)*(veca-vecb)=8and|veca|=8|vecb|.

    Text Solution

    |

  3. Show that |veca|vecb+|vecb|veca is perpendicular to |veca|vecb-|vecb|...

    Text Solution

    |

  4. If the vertices A,B, C of a triangle ABC are (1,2,3),(-1, 0,0), (0, 1,...

    Text Solution

    |

  5. If |a|=3,|b|=4a n d the angle between aa n db is 120^0 , then find the...

    Text Solution

    |

  6. If vectors hati-2xhatj-3yhatk and hati+ 3 x hatj + 2yhatk are orthogon...

    Text Solution

    |

  7. Let veca vecb and vecc be pairwise mutually perpendicular vectors, suc...

    Text Solution

    |

  8. If veca+vecb+vecc =0, |veca|=3, |vecb|=5, |vecc|=7 then the angle betw...

    Text Solution

    |

  9. If the angle between unit vectors veca and vecb is 60^(@) . Then find ...

    Text Solution

    |

  10. Let vecu=hai+hatj,vecv=hati-hatj and vecw=hati+2hatj+3hatk. If hatn is...

    Text Solution

    |

  11. A , B , C , D are any four points, prove that vec A B dot vec C D+ ...

    Text Solution

    |

  12. P(1,0,-1), Q(2,0,-3),R(-1,2,0)a n dS(,-2,-1), then find the projection...

    Text Solution

    |

  13. If the vectors 3 vec p+ vec q ;5p-3 vec qa n d2 vec p+ vec q ;3 vec p-...

    Text Solution

    |

  14. Let vecA and vecB be two non-parallel unit vectors in a plane. If (alp...

    Text Solution

    |

  15. If veca ,vecb, vec c are three vectors such that veca + 2 vecb + vecc ...

    Text Solution

    |

  16. If veca and vecb are unit vectors, then find the greatest value of |ve...

    Text Solution

    |

  17. Constant forces P1= hat i+ hat j+ hat k ,P2= hat i+2 hat j- hat ka n d...

    Text Solution

    |

  18. Find |veca|and|vecb|, if (veca+vecb)*(veca-vecb)=8and|veca|=8|vecb|.

    Text Solution

    |

  19. If A ,B ,C ,D are four distinct point in space such that A B is not...

    Text Solution

    |

  20. If veca=2hati+ 3hatj-5hatk,vecb =m hati+nhatj +12 hatk and veca xx vec...

    Text Solution

    |

  21. If |veca|=2, |vecb|=5 and |vecaxxvecb|=8 then find the value of veca.v...

    Text Solution

    |