化简:sin(npai-2/3pai)*cos(npai+4/3pai),n属于Z
化简sin(-2/3pai+kpai)cos(pai/6+kpai)tan(pai/4+kpai),k属于z
化简!f(x)=sin(pai-x)cos(3/2pai+x)+sin(pai+x)sin(3/2pai-x)
化简:[cos(a+pai)*sin^2(a+pai)]/[tan^2(pai+a)*cos^3a]
cos(x-pai/4)=根号2/10,x属于(pai/2,3pai/4)求sinx和sin(2x+pai/3)
已知:cos(x-pai/4)=根号2/10,x属于pai/2,3pai/4,求sin(2x+pai/3)的值
[tan(pai-a)cos(2pai-a)sin(-a+3pai/2)]/[cos(-a-pai)sin(-pai-a
cos(pai/15)×cos(2pai/15)×cos(3pai/15)×cos(4pai/15)×cos(5pai/
cos(a+b)=3/5 sin(b-pai/4)=5/13 a,b 属于(0,pai/2) 求cos(a+pai/4)
sin(pai-a)cos(-8pai-a)=60/169且a属于(pai/4,pai/2)求cosa,sina
若sin(3/2pai-A)=log8(1/4),A属于(-pai/2,0),则cos(pai/2+A)=
f(a)=[sin(pai-a)cos(2pai-a)tan(-a+3pai/2)]/[cos(-pai-a)]则f(-
已知函数f(x)=cos(2x-pai/3)+2sin(x-pai/4).sin(x+pai/4)求函数在区间[-pai