问题 填空题

函数y=sin(x+10°)+cos(x+40°),(x∈R)的最大值是______.

答案

函数y=sin(x+10°)+cos(x+40°)

=sin(x+10°)+cos(x+10°+30°)

=sin(x+10°)+cos(x+10°)cos30°-sin(x+10°)sin30°

=

1
2
sin(x+10°)+
3
2
cos(x+10°)

=sin(x+70°)

∵y=sin(x+70°)的最大值是1

∴函数y=sin(x+10°)+cos(x+40°)(x∈R)的最大值是1

故答案为:1

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