4
ææ ¹ä¸ç³»æ°å
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lga+lgb=2
lga*lgb=1/2
lg(ab)*[lg(a/b)]^2
=(lga+lgb)*(lga-lgb)^2
=2(lga-lgb)^2
=2[(lga+lgb)^2-4lgalgb]
=4
f(x)=(2^x-1+2)/(2^x-1)
=1+2/(2^x-1)
ç±äº2^xåå¢
2^x-1åå¢
2/(2^x-1)åå
æ以
f(x)=(2^x-1+2)/(2^x-1)
=1+2/(2^x-1)åå
å®ä¹åï¼2^x-1â 0ï¼xâ 0
å¼å
xâ0-æ¶f(x)â-â
xâ-âæ¶ï¼f(x)â-1
xâ0+æ¶f(x)â+â
xâ-âæ¶ï¼f(x)â1
å æ¤å¼åæ¯(-âï¼-1)ï¼(1ï¼+â)
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