sin1= cos1= sinπ= cosπ= cosπ/2=
已知 COS1+COS2+COS3=0 SIN1+SIN2+SIN3=0 求COS(1-2)的值 1 2 3是普通的角
判断函数f(x)=cos(2π-x)-x³sin1/2x的奇偶性.
化简[cos(a-π)/sin(π-a)]sin(a-π/2)cos(π/2+a)=
sin(πcosx)=cos(πsinx)
已知(3sinα+cosα)/(3cosα-sinα)=2,则2-3sin(α-3π)sin(1.5π-α)-[cos(
求证:sin^2/(sin-cos) - (sin+cos)/(tan^2 -1) =sin+cos
为什么sin(?)=cos(?)
sin(sin(sin(sin(x)=cos(cos(cos(cos(x),X等于多少?
已知向量a=(cos3/2x,sin3/2x),b=(cos1/2x,sin1/2x),x属于[0,π/2] 求f(x)
sin(π/2+α)·cos(π/2-α)/cos(π+α)+sin(π-α)·cos(π/2+α)/sin(π+α)=
sinπ/24*cosπ/24*sinπ/12=—— 答案是这么写的:1/2(2sinπ/24*cosπ/24)cosπ
已知cos(π/2+a)=2sin(a-π/2)求sin(π-a)+cos(a+π)/5cos(5π/2-a)+3sin