(Ⅰ)若f(x)在x=1处取得极值,求a的值;
(Ⅱ)若f(x)在区间(1,2)上单调递增,求a的取值范围;
(Ⅲ)讨论函数g(x)=f'(x)﹣x的零点个数.
(Ⅰ)若函数f(x)在x=2时取极值,求实数a的值;
(Ⅱ)若f(x)≥0对任意x∈[1,+∞)恒成立,求实数a的取值范围.
(Ⅰ)若a=b=1,求函数f(x)的单调区间;
(Ⅱ)若a=0,且当x≥0时,f(x)≥1总成立,求实数b的取值范围;
(Ⅲ)若a>0,b=0,若f(x)存在两个极值点x1 , x2 , 求证;f(x1)+f(x2)<e.