A:the father is ,his family are
B:.the father is , ishis family
C:is the father ,his family are
D:is the father is ,his family i
(Ⅰ)求实数a,b的值并判断函数f(x)的奇偶性;
(Ⅱ)判断函数f(x)在0,+∞)上的单调性,并证明你的结论.