已知cos(π/6-α)+sinα=(4倍根号3)/5,则cos(α-π/3)=
1个回答
左=√3/2cosα+3/2sinα=√3(1/2cosα+√3/2sinα)=√3cos(α-π/3)=4√3/5
∴cos(α-π/3)=4/5
相关问题
已知cos(α-π/6)+sinα=(4倍根号3)/5,则sin(α+7π/6)=
已知cos(π/6-α)+sinα=(4倍根号3)/5,则sin(α+7π/6)=
已知sin(7π-α)-3cos(3π/2+α)=2,则(sin(π-α)+cos(π+α))/(sinα+cos(-α
已知sin(2π-α)=[4/5],α∈(3π2,2π),则[sinα+cosα/sinα-cosα]等于( )
已知(3sinα+cosα)/(3cosα-sinα)=2,则2-3sin(α-3π)sin(1.5π-α)-[cos(
已知tanα(α+π/4)=2,α(π,(3π/2)),则(2sinα+cosα)/(3cosα-2sinα)=
已知sin(π-α)-cos(π+α)=根号2/3 (π/α
已知sin(α-π)=2cos(2π-α),求sin(π−α)+5cos(2π−α)3cos(π−α)−sin(−α)的
已知f(α)=sin(α−3π)•cos(π+α)cos(2π−α)•sin(−π−α)•sin(3π2−α)
已知f(α)=sin(α−3π)•cos(2π−α)•sin(−α+3π2)cos(−π−α)•sin(−π−α)