[微分] 應用問題

[s1990716 (小婷)]

A(square)baseball diamond has sides that are 90 feet along. A player 26 feet

from third base is running at a speed of 30 feet per second. At what rate is

the player's distance from home plate changing ?


不清楚要怎麼設式呢......
請幫忙解惑~

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※ 發信站: 批踢踢實業坊(ptt.cc) 
◆ From: 122.116.127.139
推 SDUM:dx/dt = 30 then d(90-x)/dt = -30 (．＿．?)