已知cos(π/4 -x)=1/7,sin(3π/4 +y)=11/14,π/4

已知cos(π/4 -x)=1/7,sin(3π/4 +y)=11/14,π/4 y=sin（-3x) =-sin3x y=cos(3x+π\4) =cos(π/2+3x-π/4) =-sin(3x-π 已知sin(x-3π/4)cos(x-π/4)=-1/4,则cosx等于 1.y=cos^4x+sin^4x 求周期 2.y=（sin2x+sin（2x+π/3)）/（ cos2x+cos（2x 三角函数已知P(-4,3) 求(cos((π/2)+x)sin(-π-x))/(cos((11π/2)-x)sin((9 已知函数f(x)=cos(2x-π/3)+2sin(x-π/4)sin(x+π/4) 已知函数f(x)=(1+1/tanx)sin(x)^2 -2sin(x+π/4)*cos(x+π/4) 已知函数f(x)=sin^2*x-根号3*sinπ/4*x*cosπ/4*x 函数y=【cos（3x+π/4)-sin(3x+π/4）】/[cos（3x+π/4)+sin(3x+π/4）]的定义域, 已知f(x)=cos^2x/1+sin^2x求f'(π/4) 已知函数f(x)=sin²(π/4+x)+cos²x+1/2求最值 已知函数f(x0=cos(2x-π/3)+2sin(x-π/4)sin(x+π/4)