推 pigheadthree:謝謝前輩的指導，我瞭解了，謝謝！ 02/03 16:06
→ pigheadthree:我知道我哪裡計算錯誤了，是-log_2^(3) 3 02/03 16:13
→ pigheadthree:我看成加的...........難怪會算不出來！XD 02/03 16:13
※ 引述《pigheadthree (爬山)》之銘言：
: 題目：
: (1) log_10 20 + log_10 5 = 2
: (2) log_8 12 + log_8 16 - log_8 3 = 2
: 小弟的想法：
: (1) log_10 2*10 + log_10 (1/2)*10
: = log_10 10 + log_10 2 + log_10 10 + log_10 (1/2)
: = 1 + log_10 2 + 1 + log_10 (1/2)
: = 2 + log_10 2 + log_10 (1/2)
: = 2 + log_10 2*(1/2)
: = 2 + log_10 1
: = 2 + 1og_10 10^0
: = 2 + 0*log_10 10
: = 2 + 0*1 = 2
: (2)log_2^(3) 4*3 + log_2^(3) 2^(4) + log_2^(3) 3
: =log_2^(3) 2^(2) + log_2^(3) 3 + (4/3)log_2 2 + log+2^(3) 3
: =(2/3)log_2 2 + (4/3)log_2 2 + 2*log_2^(3) 3
: =2*1 + 2*log_2^(3) 3
: =2 + (2/3)*log_2 3
: 請問版上前輩(2/3)log_2 3該怎麼計算呢？麻煩不吝嗇告知，謝謝！
太麻煩了...這兩題是很基本的秒殺題呀
(1)log_10 20 + log_10 5
=㏒_10(20×5)
=㏒_10(100)
=2
(2)log_8 12 + log_8 16 - log_8 3
=㏒_8(12×16÷3)
=㏒_8(64)
=2
這個log運算你可能要去翻課本複習一下
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