∵X∈(π/6,5π/6)
∴ sinx ∈ ( 1/2,1 ]
m^2-1=sinx
即m^2=sinx + 1
∴3/2 <m^2 ≤2
则,m的取值范围是 ﹙﹣√2 ,﹣√6 / 2 ﹚∪﹙√6 / 2 ,√2﹚