f(cos2x-3)+f(4y-2ycosx)>f(0)对x属于[0,派/2]均成立
因为是奇函数,所以f(0)=0,f(cos2x-3)=-f(3-cos2x)
f(4y-2ycosx)>f(3-cos2x)>0
所以4y-2ycosx>3-cos2x对x属于[0,派/2]均成立
y>(3-cos2x)/(2-cosx)
得y>2
f(cos2x-3)+f(4y-2ycosx)>f(0)对x属于[0,派/2]均成立
因为是奇函数,所以f(0)=0,f(cos2x-3)=-f(3-cos2x)
f(4y-2ycosx)>f(3-cos2x)>0
所以4y-2ycosx>3-cos2x对x属于[0,派/2]均成立
y>(3-cos2x)/(2-cosx)
得y>2