y=(3x^2+2)/(x^2-1)
3x^2+2=yx^2-y
(y-3)x^2=(y+2)
x^2=(y+2)/(y-3)≥0
(y+2)(y-3)≥0(y≠3)
y>3,或y≤-2
所以原函数的值域为：
(-∞,-2]∪(3,+∞)