你说的很对,来看看没有回答的问题,看到了你的这道题非常容易,怎么没人应答呢!tanatan(a+π/3)=2,求cos(2a+π/3)cos(2a+π/3)=cosacos(a+π/3)-sinasin(a+π/3)=cosacos(a+π/3)[1-tanatan(a+π/3)=-cosacos(a+π/3)2...