设sin(π/4-x)=5/13,则cos2x/cos(π/4-x)=_______

设sin(π/4-x)=5/13,则cos2x/cos(π/4+x)=_______ 设sin(π/4-x)=5/13,则cos2x/cos(π/4-x)=_______ 设f(x)=sin(x+4/π),则f(2x)= 设sin（45-x）=5/13,0 设f(cos^2x)=sin^2x,则f'(π/4)等于, 设f(x)={sinπx(x 设f(x)={sinπx(x 设 f(x)= {sinπx(x 设f(x)={sinπx(x 设f(x)=(1+cos2x)/2sin(π/2-x)+sinx+a^2sin(x+π/4)的最大值为√2+3,则常数a= 设函数f(x)=sin(πx/2+π/4)x 设函数 f(x)=sin(2x+y),(-π 设函数f(x)=sin(2x+φ)(-π 设函数f(x)=sin(2x+φ)(-π 设函数f x=SIN(2X+φ)(-π 设函数f(x)=sin(2x+φ)(-π 设函数f(x)=sin(2x+φ)(-π 设函数f(x)=sin(2x+φ)(-π