sin(x+y)sin(x-y)=m,则cosx的平方-cosyd 平方的值为?

设sin(x+y)sin(x-y)=m,则cos^2x-cos^2y的值 求证sin²x-sin²y=sin(x+y)sin(x-y) 已知(sinx)2-(siny)2=m求sin(x y)sin(x-y)求sin(x+y)sin(x-y) sin（x+y）*sin（y-x）=m,cosx的平方-cosy的平方? Mathematica y''+ sin(x) y=x 证明sin(x+y)sin(x-y)=sinx-siny sin(x+y)sin(x-y)=m,则(cosx)^2-(cosy)^2的值为求具体过程,谢谢! sin(x+y)sin(x-y)=m,则cosx的平方-cosyd 平方的值为? y=sin根号x y=sinx+sin|x| 已知sin(x+y)/cos(x-y)=m/n,则tanx/tany=? sin(x.y)中, sin(x)^y求导 一道三角恒等式证明题请证明sin(x+y)sin(x-y)=sin^2(x)-sin^2(y) y=[sin^2(x)]*[sin^2(x)]求导 已知sinx=1/3,sin(x+y)=1,则sin（2y+x)= 已知sin(x+y)=1/3,sin(x-y)=1/5,则tanx/tany y=(sin x + COS x)^2