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

问题描述:

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

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