1.

if x = root 3 + root 2/ root 3 - root 2 nd y =3 root - root 2 /root 3 = root 2 find the value of x square y square +xy

Answer» HEY friend,
Here is the ANSWER you were looking for:
x =  \frac{ \sqrt{3}  +  \sqrt{2} }{ \sqrt{3} -  \sqrt{2}  }

On Rationalizing the denominator we get,

x =  \frac{ \sqrt{3} +  \sqrt{2}  }{ \sqrt{3}  -  \sqrt{2} }  \times   \frac{ \sqrt{3}  +   \sqrt{2}  }{ \sqrt{3}   +   \sqrt{2} }  \\  \\

Using the identities:

{(a + b)}^{2}   =  {a}^{2}  +  {b}^{2}  + 2ab \\ (a + b)(a - b) =  {a}^{2}  -  {b}^{2}


x =  \frac{ {( \sqrt{3}) }^{2}  +  {( \sqrt{2} )}^{2} + 2( \sqrt{3})( \sqrt{2}  ) }{ {( \sqrt{3} )}^{2} -  {( \sqrt{2}) }^{2}  }  \\  \\  x =  \frac{3 + 2 + 2 \sqrt{6} }{3 - 2}  \\  \\ x = 5 + 2 \sqrt{6}  \\  \\ y =  \frac{ \sqrt{3} -  \sqrt{2}  }{ \sqrt{3}  +  \sqrt{2} }

On rationalizing the denominator we get,

y =  \frac{ \sqrt{3}  -  \sqrt{2} }{ \sqrt{3}   +  \sqrt{2} }  \times  \frac{ \sqrt{3}  -  \sqrt{2} }{ \sqrt{3}  -  \sqrt{2} }  \\

Using the identities:

{(a - b)}^{2}  =  {a}^{2}  +  {b}^{2}  - 2ab \\ (a + b)(a - b) =  {a}^{2}  -  {b}^{2}  \\

y =  \frac{ {( \sqrt{3}) }^{2}  +  {( \sqrt{2}) }^{2}  - 2( \sqrt{3})( \sqrt{2}  )}{ {( \sqrt{3} )}^{2} -  {( \sqrt{2} )}^{2}  }  \\  \\ y =  \frac{3 + 2 - 2 \sqrt{6} }{3 - 2}  \\  \\  y = 5 - 2 \sqrt{6}

Now,

Bro I GUESS you have forgot a sign in between x sq and y sq

So, for that I can solve putting both + and -

Here we go:

{x}^{2}  +  {y}^{2}   + xy \\  \\  {(5 + 2 \sqrt{6} )}^{2}  +  {(5 - 2 \sqrt{6} )}^{2}  + (5 + 2 \sqrt{6} )( 5 - 2 \sqrt{6} ) \\


Using same identities:


( {(5)}^{2}  +  {(2 \sqrt{6}) }^{2}  + 2(5)(2 \sqrt{6} )) + ( {(5)}^{2}  +  {(2 \sqrt{6}) }^{2}  - 2(5)(2 \sqrt{6}))  + (5 + 2 \sqrt{6} )(5 - 2 \sqrt{6} ) \\  \\  = (25 + 24 + 20 \sqrt{6} ) + (25 + 24 - 20 \sqrt{6} ) + ( {(5)}^{2} -  {(2 \sqrt{6} )}^{2}  ) \\  \\  = 49 + 20 \sqrt{6}  + 49  - 20 \sqrt{6}  + (25 - 24) \\  \\  = 98 + 1 \\  \\  = 99

And if the question is,


{x}^{2}   -   {y}^{2}  + xy \\  \\  = (5 + 2 \sqrt{6} )^{2}  - (5 - 2 \sqrt{6} )^{2}  + (5 + 2 \sqrt{6} )(5 - 2 \sqrt{6} ) \\  \\  = ( {(5)}^{2}  +  {(2 \sqrt{6} )}^{2}  + 2(5)(2 \sqrt{6} )) - ( {(5)}^{2}  +  {(2 \sqrt{6}) }^{2}  - 2(5)(2 \sqrt{6} )) - ( {(5)}^{2}  -  {(2 \sqrt{6}) }^{2} ) \\  \\  = (25 + 24 + 20 \sqrt{6} )  - (25 + 24 - 20 \sqrt{6} ) - (25 - 24) \\  \\  = 25 + 24 + 20 \sqrt{6}  - 25 - 24 + 20 \sqrt{6}  + 1 \\  \\  = 40 \sqrt{6}  + 1

Hope you have got your answer !!!

If you have any doubt regarding to my answer, FEEL free to ask in the COMMENT section or inbox me if needed.

@Mahak24

Thanks...
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