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※ 編輯: matmoki 來自: 122.117.188.214 (12/01 00:18)
※ 引述《victor7935 (victor)》之銘言：
: The base of an isoceles triangle is 6 feet.
: Given that the altitude is 4 feet and increasing
: at the rate of 2 inches per minute,at what rate is the
: vetex angle changing ?
: 不大懂題目的意思...
: 幫忙一下囉! Thanks!
高L 一半底邊S 1 feet = 12 inch ......
tan(θ/2)=S/L θ=arctan(S/L)*2
-S(dL/dt)
-----2----
L
dθ/dt = -------2----*2 = -6*2/(25*12) = -0.04
1 + S
--2-
L
--
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