y=(mx^2+4√3x+n)/(x^2+1)
(m-y)x^2+4√3x+n-y=0
上方程未知数为x的判别式△≥0
即(4√3)^2-4(m-y)*(n-y)≥0
y^2-(m+n)y+mn-12≤0
[m+n-√(m^2+n^2-2mn+48)]/2≤y≤[m+n+√(m^2+n^2-2mn+48)]/2
已知y=(mx^2+4√3x+n)/(x^2+1)(m