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问题: 解

当π/2<=x<3/2π时,方程sinx+|cosx|=π/3的解的个数是

解答:

当π/2≤x<3/2π时,|cosx|=-cosx
∴方程sinx+|cosx|=π/3,即
方程sinx-cosx=π/3,即
√2sin(x-π/4)=π/3
1>sin(x-π/4)=π/(3√2)>√2/2
y=sin(x-π/4)的图象在π/2≤x<3/2π上与直线y=π/(3√2)有两个交点
∴当π/2<=x<3/2π时,方程sinx+|cosx|=π/3的解的个数是 2