ctm_0011

It is given that s is the sum of two parts, one part varies directly as t and the other part varies inversely as t. When t=1, s=5/2. When t=2, s=2.Find the equation connecting s and t.THX~

[ 本帖最後由 MrDon 於 2011-7-19 01:08 AM 編輯 ]

s00100630

s=kt+L/t , where k and L are constant
when t=1, s=5/2
5/2=k+L   -------(1)
when t=2, s=2
2=2k+L/2
4=4k+L    -------(2)

(2)-(1)
3k=3/2
k=1/2=0.5

Sub k=0.5 into(2),
4=2+L
L=2

So, the equation is s=t/2+2/t