Maths
2015-02-12 9:56 pm
Peter said the expression u = 40 + 4w + 300/w^2 can be expressed as Y = k/X where Y is a function of u, X is a function of w and k is a constant. Find Y, X and k.
回答 (2)
2015-02-13 6:06 am
✔ 最佳答案
u =40 + 4w + (300/w)u = 4 (10w + w² + 75) / w
u = 4 / [w / (w² + 10w + 75)]
Compare with Y = k/X :
Y = u
k = 4
X = w / (w² + 10w + 75)
There are many alternative answers, such as :
Y = u
k = 8
X = 2w / (w² + 10w + 75)
etc.
2015-02-13 12:24 am
不明白本題的用意，由於沒有規定，很多 transformation 也成立，例如：
u = 40 + 4w + 300/w
u = (40w + 4w² + 300)/w
u = 1/[w/(40w + 4w² + 300)]
那我可否令 Y = u, k = 1, X = w/(40w + 4w² + 300)？
明顯地可以，所以不確定你的題目要問什麼．．．
u = 40 + 4w + 300/w
u = (40w + 4w² + 300)/w
u = 1/[w/(40w + 4w² + 300)]
那我可否令 Y = u, k = 1, X = w/(40w + 4w² + 300)？
明顯地可以，所以不確定你的題目要問什麼．．．
收錄日期: 2021-04-15 18:14:36
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20150212000051KK00037