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Mesaj |
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log sqrt2(5^x-1)*log sqrt2(2sqrt2/5^x-1)>=2
--- deathcrush.
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5^x-1>0 => 5^x>1 =>x>0
baza ramane sqrt(2)
logsqrt(2)(5^x-1)*[3-logsqrt(2)(5^x-1)]>_2
logsqrt(2)(5^x-1)=t
t(3-t)>_2 => t^2-3t+2<_0 =>t apartine [1,2]
1<_ t <_2
1<_logsqrt(2)(5^x-1) <_2
sqrt(2)<_5^x-1<_2
sqrt(2)+1<_ 5^x<_3
log5[sqrt(2)+1]<_ x<_ log5(3)
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multumesc mult...
--- deathcrush.
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