y=(x+sinx)/(1+x^2) 证明有界性

证明 [sin(2x+y)/sinx]-2cos(x+y)=siny/sinx 证明y=x+sinx不是周期函数 证明sin(x+y)sin(x-y)=sinx-siny 函数设y=sinX 证明Δy=2cos(X+1/2ΔX)sin1/2ΔX sin(x+y)-sinx=2cos(x+1/2y）sin(1/2y)的详细证明步骤. 证明sinx+siny+sinz-sin(x+y+z)=4sin((x+y)/2)sin((x+y)/2)sin((x+ 证明y=(x+sinx)/x是有界函数 请问,如何证明sinx+siny=2*sin(x+y/2)*cos(x-y/2) 证明sin(x+y)sin(x-y)=（sinx）^2-(siny）^2. 证明cosx(cosx-cosy)+sinx(sinx-siny)=2sin(x-y)/2 判断函数y=lg[sinx++√(1+sin^2x)]的奇偶性并证明 函数有界性证明如何证明(1)y=1-sinx+7cos3x(2)y=(arctanx)/(1+x^2)的有界性?