题目

已知y＝f(x)是R上的奇函数，且当x>0时，f(x)＝－x2＋2x＋2. (1)求f(x)的解析式； (2)画出f(x)的图象，并指出f(x)的单调区间． 答案：(1)  (2) 图略,f(x)在上单调递减，在上单调递增The girl has _________ to do today.A. lots of homework B. a lot of homeworksC. a lot homework D. lots of homeworks