(I)求实数的值;
(Ⅱ)若 , , , 求点到平面的距离.
参考数据:若 , 则 , , .
(Ⅰ)若f(x)在x=x1 ,x2(x1≠x2)处导数相等,证明:f(x1)+f(x2)>8−8ln2;
(Ⅱ)若a≤3−4ln2,证明:对于任意k>0,直线y=kx+a与曲线y=f(x)有唯一公共点.