Math, asked by stargirl0842006, 1 year ago

Answer me....pls...........​

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Answered by jahanvisaraswat
9

Answer:

1. 14

2. -8√3

Step-by-step explanation:

please refer to the photo attached....

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Answered by Anonymous
23

x = 2 - √3

___________ [ GIVEN ]

• We have to find the value of x² + \dfrac{1}{ {x}^{2} } and x² - \dfrac{1}{ {x}^{2} }

______________________________

• x = 2 - √3 ______ (eq 1)

\dfrac{1}{x}\:=\: \dfrac{1}{2 \:  - \:   \sqrt{3} }

=> \dfrac{1}{2 \:  - \:   \sqrt{3} } \:  \times  \:  \dfrac{2 \:  +  \: 3}{2 \:  +  \:  \sqrt{3} }

We know that ..

(a - b) (a + b) = a² - b²

=> \dfrac{2 \:  +  \: \sqrt{3}}{ {(2)}^{2}  \:  -  \:  (\sqrt{3})^{2} }

=> \dfrac{2 \:  +  \: \sqrt{3} }{ 4  \:  -  \:  3}

=> \dfrac{2 \:  +  \: \sqrt{3} }{ 1}

=> 2 + √3 _____ (eq 2)

______________________________

Now..

• x + \dfrac{1}{x} = 2 - √3 + 2 + √3

=> 4

Now.. squaring on both sides ..

=> \bigg(x \:  +  \:  \dfrac{1}{x} \bigg )^{2} = (4)²

=> x² + \dfrac{1}{ {x}^{2} } + 2x × \dfrac{1}{x} = 16

=> x² + \dfrac{1}{ {x}^{2} } = 16 - 2

=> x² + \dfrac{1}{ {x}^{2} } = 14

____________________________

We also have to find the value of x² - \dfrac{1}{{x}^{2}}

We have x = 2 - √3

Now .. squaring on both sides

=> x² = (2 - √3)²

=> (2)² + (√3)² - 2(2)(√3)

=> 4 + 3 - 4√3

=> 7 - 4√3

Also we have • \dfrac{1}{x}\:=\: \dfrac{1}{2 \:  - \:   \sqrt{3} }

Squaring on both sides ..

=> \dfrac{1}{ {x}^{2} } = (2 + √3)²

=> (2)² + (√3)² + 4√3

=> 7 + 4√3

So..

• x² - \dfrac{1}{ {x}^{2} } = 7 - 4√3 - (7 + 4√3)

=> 7 - 4√3 - 7 - 4√3

=> - 8√3

_____________________________

x² + \dfrac{1}{ {x}^{2} } = 14 and x² - \dfrac{1}{ {x}^{2} } = - 8√3

________ [ ANSWER ]

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