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If for a unit vector a.(x-a).(x+a)=12, then |x| is equal to |
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Answer» 4 [` :'`Itis a unitvector, mangnitude of unitvector is 1 ] ` therefore(x-a).(x+a)=12` `IMPLIES x.x+x.a-a.x-a.a=12` `[ :'a.a =|a|^(2) anda.b=b.a]` `implies |x|^(2)-|a|^(2) = 12implies |x|^(2) -1^(2)=12` `[ :'|a|=1 ` asit is unitvector ] ` | x|^(2)= 13gt |x|= sqrt(13)` |
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