Math, asked by andisk, 1 year ago

if x=3+2√2 then find value of x+1/x

Answers

Answered by sumo2
5
x=3+2root2
1/x=1/(3+2root2)=(3-2root2 )/[3^2-(2root2 )^2]
=(3-2root2 )/(9-8)=3-2root2
so x+1/x=3+2root2 +3-2root2 =6
Answered by BrainlyQueen01
18
Hey mate!

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Given ;

x = 3 + 2 \sqrt{2}

To find :

x +  \frac{1}{x}
Solution :

x = 3 + 2 \sqrt{2}  \\  \\  \frac{1}{x}  =  \frac{1}{3 +  2\sqrt{2} }  \times  \frac{3 -  2 \sqrt{2} }{3 - 2 \sqrt{2} }  \\  \\  \frac{1}{x}  =  \frac{3 -  \sqrt{2} }{(3) {}^{2}  - (2 \sqrt{2}) {}^{2}  }  \\  \\  \frac{1}{x}  =  \frac{3 - 2 \sqrt{2} }{9 - 8}  \\  \\  \frac{1}{x}  = 3 - 2 \sqrt{2}
Now

x +  \frac{1}{x}  \\  \\ 3 + 2 \sqrt{2}  + 3 - 2 \sqrt{2}  \\  \\  = 3 + 3 \\  \\  = 6


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Thanks for the question !

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