Question

*If x = 1 + √2, then show that : ( x - 1/x) whole cube = 8


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Answer 1

Step-by-step explanation:

x = 1 + √2

( x - 1/x)^3 = ( 1 + √2 - ( 1 / (1+√2) ) )^3

=( 1 + √2 - ( 1 / (√2+1))((√2-1)/(√2-1)))^3

=(1+√2-((√2-1)/(((√2)^2)-(1^2))))^3

=(1+√2-√2+1)^3

=2^3

=8

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