已知tan(α+6π⼀5)=m(m≠1),求sin[(11π⼀5)+α]+3cos(α-9π⼀5)⼀sin[(14π⼀5)-α]+cos(α+16π⼀5)的值

2025-03-02 11:41:38
推荐回答(1个)
回答1:

由条件推出tan(α+π/5)=-m
sin(α+π/5)=-mcos(α+π/5)
原式=/
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=<-mcos(π/5+α)+3cos(α+π/5)>/<-mcos(4π/5-α)-cos(α+π/5)>
=(-m+3)/(-m-1)
=(m-3)/(m+1)