64-4(1-m^2)(4-4m^2)≥0
64-(4-4m^2)(4-4m^2)≥0
64-(16-32m^2+16m^4)≥0
-16m^4+32m^2+48≥0
m^4-2m^2-3≤0
(m^2-3)(m^2+1)≤0
两个都采纳吧.