Find the greatest and least vaule of each of the following expressions.
1.7+3sinx-4cosx
2.3/(5cosx-12sinx+16)
sin,cos questions!
2008-03-11 6:24 am
回答 (1)
2008-03-11 6:46 am
✔ 最佳答案
1. 7+3sinx-4cosx=3sinx-4cosx+7
=5[sinx(3/5)-cosx(4/5)]+7
=5sin(x-59.03)+7
The greatest vaule=5(1)+7
=12
The least value=5(-1)+7
=2
2. 3/(5cosx-12sinx+16)
=3/13{[cosx(5/13)-sinx(12/13)]+16}
=3/[13cos(x+74.87)+16]
The greatest vaule=3/[13(-1)+16]
=1
The least value=3/[13(1)+16]
=3/29
收錄日期: 2021-04-23 20:32:58
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