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Find |veca|and|vecb|, if (veca+vecb)*(ve...

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

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`(veca+vecb) .(veca-vecb) =8`
`or veca.veca-veca.vecb+vecb.veca-vecb.vecb=8`
`or |veca|^(2) -|vecb|^(2)=8`
`or (8|vecb|)^(2)-|vecb|^(2)=8 " " [|veca|=8|vecb|]`
`or |vecb|=sqrt(8/63)`
`or |veca|=8|vecb|=(8xx2sqrt2)/(3sqrt7)= (16sqrt2)/(3sqrt7)`
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CENGAGE-DIFFERENT PRODUCTS OF VECTORS AND THEIR GEOMETRICAL APPLICATIONS -Exercise
  1. Find |veca|and|vecb|, if (veca+vecb)*(veca-vecb)=8and|veca|=8|vecb|.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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