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If x = 3 - 2√2 , find x² + 1/x² |
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Answer» 1/x = 1/( 3 - 2√2 ) = ( 3 + 2√2 ) / [1/x = 1/( 3 - 2√2 = ( 3 + 2√2 ) / [ 3² - ( 2√2 )² ] = ( 3 + 2√2 ) / ( 9 - 8 ) = 3 + 2√2 ----( 2 ) x + 1/x = 3 - 2√2 + 3 + 2√2 = 6 ------( 3 ) x - 1/x = 3 - 2√2 - ( 3 + 2√2 ) = 3 - 2√2 - 3 - 2√2 = - 4√2 ---- ( 4 ) Now , x² - 1/x² = ( x + 1/x ) ( x - 1/x ) = 6 × ( - 4√2 ) [ From ( 3 ) and ( 4 ) ] = - 24√2 HOPE IT HELPS |
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