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Curious Cubic Calculation? (Posted on 2004-10-13) Difficulty: 2 of 5
Show that α=√(7+5√2)+√(7-5√2) is an integer. No calculators or computers allowed!

See The Solution Submitted by Old Original Oskar!    
Rating: 3.8333 (6 votes)

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Solution inegrity by squaring | Comment 1 of 14
square both sides
simplify

I BELIEVE a IS NOT an integer

HOWEVER IF YOU TAKE DIFFERENCE INSTEAD OF A SUM:
a^2=16
a=4
or a=-4:
QED


please confirm


please see my later post
Edited on October 15, 2004, 6:12 am
  Posted by Ady TZIDON on 2004-10-13 12:49:02
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