一道三角函数题,若sin(x-y)cosy+cos(x-y)siny≥1,则x,y的取值范围分别是?(答案是x=2kπ+
2个回答
∵sin(x-y)cosy+cos(x-y)siny≥1
利用正弦公式,则
sin(x-y+y)≥1
及sinx≥1
∴sinx=1
∴x=2kπ+π/2, k ∈z
y ∈R
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