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化简:根号2sin(π/4-x)+根号6cos(π/4-x)

来源:学生作业帮 编辑:神马作文网作业帮 分类:数学作业 时间:2024/11/10 15:05:18
化简:根号2sin(π/4-x)+根号6cos(π/4-x)
(2)sin(67°-x)cos(x-22°)+cos(67°-x)cos(112°-x)的值为
化简:根号2sin(π/4-x)+根号6cos(π/4-x)
V2sin(π/4-x)+V6cos(π/4-x)
=2V2[1/2sin(π/4-x)+V3/2 cos(π/4-x)]
=2V2 Sin(π/4-x+π/3)
=2V2 Sin(7π/12-x)
sin(67°-x)cos(x-22°)+cos(67°-x)cos(112°-x)
=sin(67°-x)cos(x-22°)+cos(67°-x)cos(90°-x+22°)
=sin(67°-x)cos(x-22°)+cos(67°-x)Sin(x-22°)
=sin(67°-x+x-22°)
=Sin(45°)
=V2/2