【導(dǎo)讀】應(yīng),則稱(chēng))(xf為單值函數(shù),否則就是多值函數(shù).有對(duì)于關(guān)于原點(diǎn)對(duì)稱(chēng)設(shè),,DxD??或,則稱(chēng)函數(shù)在區(qū)間I上是單調(diào)遞減的;單調(diào)增加和單調(diào)減少的函數(shù)統(tǒng)稱(chēng)為單調(diào)函數(shù)。;0時(shí)為增函數(shù)當(dāng)?說(shuō)周期函數(shù)的周期是指其最小正周期)..)()(1稱(chēng)為反函數(shù)確定的由xfyxfy???5)反三角函數(shù);arccosxy?為x的復(fù)合函數(shù).小),總存在正數(shù)N,使得對(duì)于Nn?定義2如果對(duì)于任意給定的正數(shù)?,使得對(duì)于適合不等式????零的無(wú)窮小的倒數(shù)為無(wú)窮大.推論2常數(shù)與無(wú)窮小的乘積是無(wú)窮小.