y=sin（x+3π/4）+cos（x+3π/)的周期和是奇函数还是偶函数?

已知sinx=3/5,x∈(π/2,π),求【sin(x+y)+sin(x-y)】/【cos（x+y）+cos（x-y）】的值 当cos^2x-cos^2y=√3/2时,求sin(x+y）×sin(x-y) 证明COS（X+Y）COS（X-Y）=COS^2X-SIN^2Y y=2cos(x/4+ π/3)-3sin(x- π/4)y=sin(4x- π/3)-cos(3x+π/2) 函数y=sin(x)cos(x+ π/4)+cos(x)sin(x+π/4)的最小正周期是 y=sin^2x-3sinxcosx+4cos^2x是否等于y=sin^2x+cos^2x+3cos^2x-3/2*sin2x?y=sin^2x-3sinxcosx+4cos^2xy=sin^2x+cos^2x+3cos^2x-3/2*sin2x=1+3cos^2x-3/2*sin2x=1+3（1-sin^2x）-3/2*sin2x=-3sin^2x-3/2*sin2x+4 化简y=sin^2(x)+2sin(x)cos(x)+3cos^2(x) 已知sin(x-y)cosx-cos(y-x)sinx=3分之5,y是第三象限角,求sin(y+5π分之4）的值 sin(x-y)cosx-cos(y-x)sinx=3/5 y是第三象限角 求sin（y+5π/4） 参数方程x=cos(sin+cos)y=sin（cos+sin）化为普通方程 y =(cos^2) x - sin (3^x),求y' 求函数y=cos(9/2π+x)+sin^2x的最大值和最小值还有一题 已知sinx+cosx=1/2,求sin^3x+cos^3x和sin^4x+cos^2x Sin x-sin y=2/3 cos x-cos y=1/2 求cos(x-y) y=4sin(3x+(π/4))+3cos(3x+(π/4)),求周期 y=sin(2x-π/4)+cos(3x+π/3)的导数 函数y=sin（x+π／3）cos（π/6-x） 函数y=cos(x+π/2）+sin（π/3-x)化简 化简sin(x+7π/4)+cos(x-3π/4）步骤我已经找到撒sin(x+7π/4)+cos(x-3π/4)=sin(x+2π-π/4)+cos(x-π+π/4)我问下这一步是在干嘛?=sin(x-π/4)+cos[-(π-x-π/4)]=sin(x-π/4)+cos(π-x-π/4)=sin(x-π/4)-cos(x+π/4)=sin(x-π/4)-cos(x+π/2-