ｙ隨ａ既立方而正變，且隨ｂ而反變。如果ａ同ｂ都增加２０％，求ｙ既百分變化
[請詳解/列式]
數學題目~...幫幫我解答,thx
2007-04-04 6:24 am
回答 (3)
2007-04-04 6:30 am
✔ 最佳答案
Let y = ka^3/bNow,
a' = a(1+20%) = 1.2a
b' = b(1+20%) = 1.2b
y' = ka'^3/b'
= k(1.2a)^3/(1.2b)
= (1.2)^2 (ka^3/b)
= 1.44 y
% change in y = (y'-y)/y * 100%
= (1.44y-y)/y*100%
= 0.44*100%
=44% (increase)
2007-04-04 6:39 am
等我話比你知啦!!!!!!
就係咁嫁........
Let y = ka^3/b
Now,
a' = a(1+20%) = 1.2a
b' = b(1+20%) = 1.2b
y' = ka'^3/b'
= k(1.2a)^3/(1.2b)
= (1.2)^2 (ka^3/b)
= 1.44 y
% change in y = (y'-y)/y * 100%
= (1.44y-y)/y*100%
= 0.44*100%
=44% (increase)
就係咁嫁........
Let y = ka^3/b
Now,
a' = a(1+20%) = 1.2a
b' = b(1+20%) = 1.2b
y' = ka'^3/b'
= k(1.2a)^3/(1.2b)
= (1.2)^2 (ka^3/b)
= 1.44 y
% change in y = (y'-y)/y * 100%
= (1.44y-y)/y*100%
= 0.44*100%
=44% (increase)
2007-04-04 6:34 am
設y=ka^3/b,則ａ同ｂ都增加２０％時,有
y=k(1.2a)^3/1.2b
=ka^3*1.2^3/1.2b
=ka^3*1.2^2/b
=1.44(ka^3/b)
=ka^3/b+0.44(ka^3/b)
所以如果ａ同ｂ都增加２０％，ｙ既百分變化44％
y=k(1.2a)^3/1.2b
=ka^3*1.2^3/1.2b
=ka^3*1.2^2/b
=1.44(ka^3/b)
=ka^3/b+0.44(ka^3/b)
所以如果ａ同ｂ都增加２０％，ｙ既百分變化44％
收錄日期: 2021-04-12 18:52:09
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