Question

函數(shù)在定義域內(nèi)可導(dǎo)，其圖像如圖所示．記的導(dǎo)函數(shù)為
，則不等式的解集為   

A．	B．
C．	D．

Answer 1

A

試題分析：根據(jù)導(dǎo)數(shù)大于0時(shí)函數(shù)單調(diào)遞增，導(dǎo)數(shù)小于0時(shí)原函數(shù)單調(diào)遞減確定不等式的解集可得答案．：由圖象可知f（x）在[，1]，[2，3)遞減．如圖，∵根據(jù)導(dǎo)數(shù)大于0時(shí)函數(shù)單調(diào)遞增，導(dǎo)數(shù)小于0時(shí)原函數(shù)單調(diào)遞減，∴不等式⇒x∈[，1]∪[2，3)．
故選A．
點(diǎn)評(píng)：本題主要考查了導(dǎo)數(shù)的正負(fù)和原函數(shù)增減性的問(wèn)題，導(dǎo)數(shù)的符號(hào)決定函數(shù)的單調(diào)性：導(dǎo)數(shù)為正，函數(shù)單增；導(dǎo)數(shù)為負(fù)，函數(shù)遞減．屬基礎(chǔ)題．