基本初等函數(shù)包括一次函數(shù)、反比例函數(shù)、指數(shù)函數(shù)、冪函數(shù)、對(duì)數(shù)函數(shù)、二次函數(shù)等.常見(jiàn)的函數(shù)問(wèn)題有函數(shù)零點(diǎn)問(wèn)題、函數(shù)單調(diào)性問(wèn)題、函數(shù)不等式問(wèn)題、函數(shù)的解析式問(wèn)題、函數(shù)的實(shí)際應(yīng)用問(wèn)題等.解答函數(shù)問(wèn)題，需靈活運(yùn)用函數(shù)的性質(zhì)、圖象.下面結(jié)合實(shí)例談一談其中三類函數(shù)問(wèn)題的解法.

一、函數(shù)零點(diǎn)問(wèn)題

函數(shù)零點(diǎn)問(wèn)題主要有求函數(shù)零點(diǎn)的值或取值范圍，求函數(shù)零點(diǎn)的個(gè)數(shù)，由函數(shù)的零點(diǎn)求參數(shù)的取值范圍等.求解函數(shù)零點(diǎn)問(wèn)題主要有兩種思路：一是根據(jù)函數(shù)零點(diǎn)的定義，令函數(shù)[fx=0]，通過(guò)解方程求得方程的根，或研究方程的根的分布情況，從而求得零點(diǎn)的值或取值范圍，確定函數(shù)零點(diǎn)的個(gè)數(shù).二是將函數(shù)的零點(diǎn)視為函數(shù)圖象與x軸的交點(diǎn)的橫坐標(biāo)，只需根據(jù)函數(shù)的解析式畫(huà)出函數(shù)的圖象，研究函數(shù)圖象與x軸的交點(diǎn)的位置和個(gè)數(shù)即可.