若T(T≠0)是它的周期,f(x)=x(sinx),则对任意x,f(x+T)-f(x)=0,即(x+T)sin(X+T)-xsinx=0取x=0,则TsinT=0,于是sinT = 0,因此cosT = ±1 ...①;取x=π/2,则(T+π/2)sin(T+π/2)-π/2=0cosT = (π/2)/(T+π/2)根据①,(π/...