Math, asked by santosh155, 1 year ago

x-1/x and x2-1/x2 if x+1/x=√5

Answers

Answered by Amirverma
2
Solution of 1st one is below
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Amirverma: Answe 2 is 15/4.
Answered by Swarup1998
1
Ans.

 {x +  \frac{1}{x} } =  \sqrt{5  }  \\ or \:  \:  {(x +  \frac{1}{x}) }^{2}  = ( { \sqrt{5}) }^{2}  \\ or \:  \:  {(x -  \frac{1}{x}) }^{2}  + 4.x. \frac{1}{x}  = 5 \\ or \:  \: {(x -  \frac{1}{x}) }^{2} + 4 = 5 \\ or \:  \: {(x -  \frac{1}{x}) }^{2} \: = 1 \\  \\ then \: x -  \frac{1}{x}  = 1 \:  \:  \: or \:  \:  \: x -  \frac{1}{x}  =  - 1

When
x -  \frac{1}{x}  = 1  \:  \: then \:  \:  \\  {x}^{2}  -  \frac{1}{ {x}^{2} }   \\  = (x +  \frac{1}{x} )(x -  \frac{1}{x}) \\  =  \sqrt{5}   \times 1 \\  =  \sqrt{5}

and when
x -  \frac{1}{x}  =  - 1 \:  \:  \: then \\  {x}^{2}  -  \frac{ {1} }{ {x}^{2} } \\  = (x +  \frac{1}{x}  )(x -  \frac{1}{x} ) \\  =  \sqrt{5}  \times ( - 1) \\  =  -  \sqrt{5}


I HOPE THAT THIS HELPS YOU.
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