3^4b=121 求b

👨🏻‍🏫 學術台數學

chun yin

2006-11-11 5:18 am

點樣 3^4b=121 求b

回答 (4)

spencer_chan2000

2006-11-11 7:59 am

✔ 最佳答案

3^4b=121
log 3 ^ 4b = log 121
4b log 3 = log 11^2
4b log 3 = 2 log 11
2b log 3 = log 11
b = log 11 / (2log3)

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2006-11-14 2:01 am

你條問題原題是否(a+1)^2=3^4b,如果是,就是你將a算錯或題目錯誤。

參考: 某個網！

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穎彤

2006-11-11 5:27 am

係咪LOG數嚟架,,
我估係咁:
3^4b=121
3^4B=11^2
2blog3=2log11
b(4log3)=2log11
b=2log11/4log3

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[匿名]

2006-11-11 5:24 am

log(base:3)121=4b

b = [log(base:3)121]/4

= 1.09(3 sig.fig.)

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