作业帮唔..sos...数学达人请...头晕ing..取lg2=0.3010,则lg2.5=_____偶基道答案是0.3980..but只会一半- -1汗呜..刚学对数`那个叫晕菜...题目它认识咱,咱不认识它- -1..教下呢～感激ing...
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唔..sos...数学达人请...头晕ing..取lg2=0.3010,则lg2.5=_____偶基道答案是0.3980..but只会一半- -1汗呜..刚学对数`那个叫晕菜...题目它认识咱,咱不认识它- -1..教下呢～感激ing...
唔..sos...数学达人请...头晕ing..
取lg2=0.3010,则lg2.5=_____
偶基道答案是0.3980..but只会一半- -1汗
呜..刚学对数`那个叫晕菜...题目它认识咱,咱不认识它- -1
..教下呢～感激ing...
唔..sos...数学达人请...头晕ing..取lg2=0.3010,则lg2.5=_____偶基道答案是0.3980..but只会一半- -1汗呜..刚学对数`那个叫晕菜...题目它认识咱,咱不认识它- -1..教下呢～感激ing...
1
lg2.5
=lg(5/2)=lg5-lg2=1-2lg2=1-2*0.3010=0.3980
补充：
lg2+lg5=1
lg(a/b)=lga-lgb
lg2=0.3010,则
lg2.5=lg5-lg2=1-lg2-lg2=1-0.6020=0.3980
lg2.5=lg(10÷2÷2)=lg10-lg2-lg2=1-0.3010-0.3010=0.398
把2.5化为10/4，
即：lg2.5=lg(10/4)=lg10-lg4=1-2lg2