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1. x2 -4x +1 =0

  • A. 43
  • B. 43
  • C. 43
  • D. 43

Answer: Option D

Explanation:

x2-4x +1=0

x2  +1  =  4x

x2/x   +1/x  = 4x/x

x+1/x=4

 

Now,  

We know,

(x-1/x)2 = (x+1/x)2-4.x.1/x

(x-1/x)2 = (4)2-4

x-1/x = 2√3

 

x2-1/x2 = (x+1/x) ((x-1/x) = 4×2√3 = 8√3

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