引用:
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作者argentala
log (X/Y) = log X - log Y
log XY = log X + log Y
log 4 = log ( 2的"2"次方) = 2x log2
log 8 = log ( 2的"3"次方) = 3x log2
log 50 = log (5x10) = log 5 + 1 = log (10/2) + 1 = (1-0.3010) +1
或是 log50 = log (100/2) = log 100 - log 2
= 1.6990
log 2=0.3010
log 3=0.4771
log 7=0.8451
背這三個就夠了 其他都用算的才不用背那麼多
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所以log50=log100/2=log100 - log2 = 2 - 0.3010 = 1.6990
記這3個就夠了，
不過我都是用EXCEL來做，方便很多，還可以一起算全對數表∼
