(1)当x≤0时,f(x)=-4x/(x+4),-x≥0,f(x)是奇函数,则f(-x)=-f(x)=4x/(x+4),f(x)=4x/(x-4).所以,f(x)=﹛-4x/(x+4),x≤0;4x/(x-4),x>0.
(2)f(2m+1)+f(m²-2m-4)>0,f(2m+1)>-f(m²-2m-4)=f(-m²+2m+4).f(x)在R单调递减,只需2m+1
(1)当x≤0时,f(x)=-4x/(x+4),-x≥0,f(x)是奇函数,则f(-x)=-f(x)=4x/(x+4),f(x)=4x/(x-4).所以,f(x)=﹛-4x/(x+4),x≤0;4x/(x-4),x>0.
(2)f(2m+1)+f(m²-2m-4)>0,f(2m+1)>-f(m²-2m-4)=f(-m²+2m+4).f(x)在R单调递减,只需2m+1