2sin(x-π/4）sin（x+π/4）=（sinx-cosx）（sinx+cosx）=-cos2a而我做的2sin(x-π/4）sin（x+π/4）=2cos(x+π/4）sin（x+π/4）=sin（2x+π/2）=cos2a差个符号?

sin(x+π/4) 2sin(x+π/4)sin(x-π/4)=? sin^2(π/4 +x) sin（x+π）的奇偶性sin(x+π)的奇偶性sin(x+π/2)的奇偶性sin(x+π/4)的奇偶性 化简2sin^2[(π/4)+x]+根号3（sin^x-cos^x）-1 傅里叶级数作图f（x）=2sin[x] - sin[2x] + 2/3sin[3x] - 1/2sin[4x]我用mathematica输入程序Plot[{2sin[x],-2sin[x],2sin[x] - sin[2x],-2sin[x] + sin[2x],2sin[x] - sin[2x] + 2/3sin[3x],-2sin[x] + sin[2x] - 2/3sin[3x],2sin[x] - sin[2x] + 2/3si 求证:(sin 2x /(1-cos 2x) )·(sin x /(1+sin x))=tan (π/4-x/2). 2sin(x-4/π）sin(x+4/π） f(x)=（1+cotx)sin^2x-2sin(x+π/4)sin(x-π/4)还有一题, 已知函数f(x)=(1+1 anx)sin^2x+m sin(x+π/4)sin(x-π/4) sin(x+π/4)sin(x-π/4)等于什么? 已知sin(x+π/6)=1/4,求sin(5π/6-x)+sin^2(π/3-x) f（x)=sin(2x+π/6）+2sin（x-π/4）sin（x+π/4） 怎么化简为形函数 根号2sin(x+π/4)化简 函数f(x)=2sin(x+π/4)sin(x-π/4)+sin2x的值域 求f【x】=2sin[x+π/4]sin[x-π/4]+sin2x的最大值 定积分0到π x*((sin(x))^2-(sin(x))^4)^(1/2) 已知sin(π/2-x)+sin(π-x)/cos(-x)+sin(2π-x)=2009,则tan(x+5π/4)等于?已知sin(π/2-x)+sin(π-x)/cos(-x)+sin(2π-x)=2009,则tan(x+5π/4)等于（） A.-2009 B.-1/2009 C.1/2009 D.2009