Question

if x + 1/x = 12 then find x - 1/x
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Answer 1

Step-by-step explanation:

( x + 1 / x ) = 12

we know that exapansion

( x + 1 / x )^2 = x^2 + 1 / x^2 + 2

x^2 + 1 / x^2 = ( x + 1 / x ) ^2 -2

x^2 + 1 / x^2 = ( 12 )^2 -2

x^2 + 1 / x^2 = 144 - 2

x^2 + 1 / x^2 = 142 -------( 1)

we know that exapansion

( x - 1 / x )^2 = x^2 + 1 / x^2 -2

= 142 - 2

= 140

taking square root both side

( x - 1 / x ) = root ( 140 )

( x - 1 / x ) = root ( 4 × 35 )

( x - 1 / x ) = 2 root ( 35 )