题目
函数y=3sin(x+20°)+5sin(x+80°)的最大值为 ______.
提问时间:2021-03-27
答案
y=3sin(x+20°)+5sin(x+80°)
=3sin(x+20°)+5sin(x+20°+60°)
=3sin(x+20°)+5[sin(x+20°)cos60°+cos(x+20°)sin60°]
=3sin(x+20°)+
sin(x+20°)+
=3sin(x+20°)+5sin(x+20°+60°)
=3sin(x+20°)+5[sin(x+20°)cos60°+cos(x+20°)sin60°]
=3sin(x+20°)+
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2 |