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cos计算公式?

cosx=3/5 x∈(0,π/2) 求cos(x+π/3) x∈(0,π/2),所以sinx>0, 由cos2x+sin2x=1得:sinx=4/

5 cos(x+π/3) =cosxcos(π/3)-sinxsin(π/3) =3/5·1/2-4/5·√3/2 =(3-4√3)/10  

匿名回答于2022-09-05 16:30:07


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