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Grade 12Mechanics

Let a→, b→, c→ be unit vectors such that a→ . b→ = a→ . c→ = 0 and the angle between b→ and c→ is π6 . Prove that a→ = ± 2()

Profile image of ETRAJA
9 Years agoGrade 12
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1 Answer

Profile image of Vikas TU
9 Years ago
 As mentioned in the question
a→ . b→ = a→ . c→ = 0
and we also know that a→ . b→  = | a→ || b→  |cos Ѳ
a→ . c→ =| a→| | c→ | cosѲ = 0
b→. c→ = | c→| | b→| cos 30
                 = (| c→| | b→| √3)/2
c→ =(| c→| | b→| √3)/(2. b→)
  • | a→| = ± 2