(1)设派x名消防员前去救火,用t分钟将火扑灭,总损失为y元,则t=
=5×100 50x?100
,10 x?2
(2)y=灭火材料、劳务津贴+车辆、器械、装备费+森林损失费
=125tx+100x+60(500+100t)
=125x
+100x+30000+10 x?2
60000 x?2
方法一:y=1250?
+100(x-2+2)+30000+x?2+2 x?2
60000 x?2
=31450+100(x-2)+
62500 x?2
≥31450+2
=36450,
100×62500
当且仅当100(x-2)=
62500 x?2
即x=27时,y有最小值36450.
答:应该派27名消防员前去救火,才能使总损失最少,最少损失为36450元、
方法二:y′=
+100-1250(x?2?x) (x?2)2
=100-60000 (x?2)2
,62500 (x?2)2
令100-
,=0,62500 (x?2)2
解得x=27或x=-23(舍)
当x<27时y′<0,当x>27时y′>0,
∴x=27时,y取最小值,最小值为36450元,
答:应该派27名消防员前去救火,才能使总损失最少,最少损失为36450元.