[微積] 梯子問題
長 39(ft)靠著牆壁，以每秒6(ft)拉梯子的底端
要求當梯子的底部遠離牆壁15(ft)時是多快的速度
Ans:-5/2 (ft/s)
我列的式子為 x(t)^2+y(t)^2=39^2
可是一次微分後 不知道x(t) 跟 y(t)要代什麼
他只有給答案，我算完一次微分後就卡住了= =
不知道有沒有人能為我解答 感謝
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題目:
A ladder 39 feet long is leaning against the wall of the a house.
The base of the ladder is pulled away from the wall at a rate of rate
6 feet per second. How fast is the top moving down when the base of
the ladder is 15 feet from the wall?
※ 編輯: FoggyCloud 來自: 111.249.92.94 (07/13 23:20)
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