if i invest $20,000 at 2.5% today, how long will it take to reach a min of $50,000
compounded semi-annually
ans is 50,000 = 20,000 (1 + 2.5%)^n
2.5 = 1.025^n 唔識禁機 (casio fx-3900pv)
n = 38 (approx)
點樣可以38 出來....?
THX
n次方 唔識禁機
2010-06-01 2:54 am
回答 (2)
2010-06-01 3:02 am
✔ 最佳答案
2.5 = 1.025^nlog (2.5)=log (1.025^n)
log (2.5)=n*[log (1.025)]
n=[log (2.5)]/[log (1.025)]=37.1
2010-06-01 6:11 am
n 次方 系無得禁架
你要做既應該系將n做subject....
50000=20000(1.025)^n
2.5=1.025^n
ln2.5= nln1.025
(ln2.5) / (ln1.025) = n
呢個時候就可以禁機啦 （記得用括弧括住來禁....)
n=37.10788 ~ 37
你個approx都唔多准ｂｏｒ.....
2010-05-31 22:12:26 補充：
ln 系 natural log
base 唔系10 系 e
你要做既應該系將n做subject....
50000=20000(1.025)^n
2.5=1.025^n
ln2.5= nln1.025
(ln2.5) / (ln1.025) = n
呢個時候就可以禁機啦 （記得用括弧括住來禁....)
n=37.10788 ~ 37
你個approx都唔多准ｂｏｒ.....
2010-05-31 22:12:26 補充：
ln 系 natural log
base 唔系10 系 e
收錄日期: 2021-04-13 17:16:42
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