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问题: 方程sinx/2-cosx/2=1的解集是

解答:

sin(x/2)-cos(x/2)=1
(√2)sin[2x-(π/4)]=1
sin[2x-(π/4)]=√2/2
所以:
2x-(π/4)=2kπ+arcsin(√2/2)
2x-(π/4)=2kπ+π/4 或2x-(π/4)=2kπ+3π/4
x=kπ+π/4,或 x=kπ+π/2,k∈Z