锟斤拷锟斤拷一锟斤拷锟�锟斤拷锟斤拷一锟斤拷(g锟斤拷)變锟斤拷锟絕(gu锟斤拷)锟斤拷锟叫ｏ拷锟叫兩傦拷(g锟斤拷)變锟斤拷x锟斤拷y锟斤拷锟斤拷锟斤拷o锟斤拷一锟斤拷(g锟斤拷)x值锟斤拷锟斤拷锟斤拷(y锟斤拷ng)锟侥就確锟斤拷唯一锟斤拷一锟斤拷(g锟斤拷)y锟斤拷锟斤拷锟斤拷锟斤拷小锟斤拷锟斤拷锟斤拷锟侥猴拷锟斤拷(sh锟斤拷)锟斤拷锟絇(gu锟斤拷n)锟斤拷锟筋總锟結(ji锟斤拷)锟斤拷請(q锟斤拷ng)锟斤拷锟斤拷锟絎(xu锟斤拷)锟斤拷(x锟斤拷)锟斤拷

锟斤拷锟斤拷1.锟斤拷锟斤拷(sh锟斤拷)锟侥革拷锟筋：锟絆(sh锟斤拷)A锟斤拷B锟角非空的旓拷(sh锟斤拷)锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟侥筹拷锟�(g锟斤拷)锟絖锟斤拷锟侥岋拷(du锟斤拷)锟斤拷(y锟斤拷ng)锟絇(gu锟斤拷n)系f锟斤拷使锟斤拷(du锟斤拷)锟节硷拷锟斤拷A锟叫碉拷锟斤拷锟斤拷一锟斤拷(g锟斤拷)锟斤拷(sh锟斤拷)x锟斤拷锟节硷拷锟斤拷B锟叫讹拷锟斤拷唯一锟絖锟斤拷锟侥旓拷(sh锟斤拷)f(x)锟斤拷锟斤拷锟斤拷(du锟斤拷)锟斤拷(y锟斤拷ng)锟斤拷锟斤拷么锟酵稱f锟斤拷A→B锟斤拷募锟斤拷锟紸锟斤拷锟斤拷锟斤拷B锟斤拷一锟斤拷(g锟斤拷)锟斤拷锟斤拷(sh锟斤拷).記锟斤拷锟斤拷y=f(x)锟斤拷x∈A.锟斤拷锟斤拷锟斤拷x锟斤拷锟斤拷锟斤拷變锟斤拷锟斤拷x锟斤拷取值锟斤拷锟斤拷A锟斤拷锟斤拷锟斤拷锟斤拷(sh锟斤拷)锟侥讹拷锟絰锟斤拷;锟絚x锟斤拷值锟斤拷锟斤拷(du锟斤拷)锟斤拷(y锟斤拷ng)锟斤拷y值锟斤拷锟斤拷锟斤拷锟斤拷(sh锟斤拷)值锟斤拷锟斤拷锟斤拷(sh锟斤拷)值锟侥硷拷锟斤拷{f(x)|x∈A}锟斤拷锟斤拷锟斤拷锟斤拷(sh锟斤拷)锟斤拷值锟斤拷.

锟斤拷锟斤拷注锟解：2锟斤拷锟街伙拷o锟斤拷锟斤拷锟斤拷式y(t锟斤拷ng)=f(x)锟斤拷锟斤拷锟絔锟斤拷指锟斤拷锟斤拷锟侥讹拷锟絰锟斤拷锟斤拷锟絫锟斤拷锟斤拷(sh锟斤拷)锟侥讹拷锟絰锟斤拷锟斤拷指锟斤拷使锟紷锟斤拷(g锟斤拷)式锟斤拷锟斤拷锟斤拷锟絰锟侥岋拷(sh锟斤拷)锟斤拷(sh锟斤拷)锟侥硷拷锟斤拷;3锟斤拷锟斤拷(sh锟斤拷)锟侥讹拷锟絰锟斤拷值锟斤拷要锟斤拷锟缴硷拷锟较伙拷^(q锟斤拷)锟絞锟斤拷锟斤拷式.

锟斤拷锟斤拷锟斤拷锟絰锟斤拷锟絘(b锟斤拷)锟斤拷

锟斤拷锟斤拷锟斤拷使锟斤拷锟斤拷(sh锟斤拷)式锟斤拷锟斤拷锟絰锟侥岋拷(sh锟斤拷)锟斤拷(sh锟斤拷)x锟侥硷拷锟较稱锟介函锟斤拷(sh锟斤拷)锟侥讹拷锟絰锟斤拷锟斤拷锟襟函旓拷(sh锟斤拷)锟侥讹拷锟絰锟斤拷r(sh锟斤拷)锟叫诧拷锟斤拷式锟組锟斤拷锟斤拷要锟斤拷锟斤拷(j锟斤拷)锟角ｏ拷(1)锟斤拷式锟侥凤拷母锟斤拷锟斤拷锟斤拷锟斤拷;(2)偶锟轿凤拷锟斤拷锟侥憋拷锟絖锟斤拷锟斤拷(sh锟斤拷)锟斤拷小锟斤拷锟斤拷;(3)锟斤拷(du锟斤拷)锟斤拷(sh锟斤拷)式锟斤拷锟芥數(sh锟斤拷)锟斤拷須达拷锟斤拷锟斤拷;(4)指锟斤拷(sh锟斤拷)锟斤拷锟斤拷(du锟斤拷)锟斤拷(sh锟斤拷)式锟侥底憋拷須达拷锟斤拷锟斤拷锟揭诧拷锟斤拷锟斤拷1.(5)锟斤拷锟斤拷锟斤拷锟�(sh锟斤拷)锟斤拷锟斤拷一些锟斤拷锟斤拷锟斤拷锟斤拷(sh锟斤拷)通锟絕(gu锟斤拷)锟侥則锟絓(y锟斤拷n)锟斤拷Y(ji锟斤拷)锟较讹拷锟缴碉拷.锟斤拷么锟斤拷锟斤拷锟侥讹拷锟絰锟斤拷锟斤拷使锟斤拷锟斤拷锟街讹拷锟斤拷锟斤拷锟絰锟斤拷x锟斤拷值锟組锟缴的硷拷锟斤拷.(6)指锟斤拷(sh锟斤拷)锟斤拷锟斤拷撞锟斤拷锟斤拷缘锟斤拷锟斤拷锟�(6)锟斤拷(sh锟斤拷)锟紿锟斤拷锟絵锟叫的猴拷锟斤拷(sh锟斤拷)锟侥讹拷锟絰锟斤拷還要锟斤拷锟紺锟斤拷(sh锟斤拷)锟紿锟斤拷锟絵锟斤拷锟斤拷锟絰.

锟斤拷锟斤拷锟斤拷(g锟斤拷u)锟缴猴拷锟斤拷(sh锟斤拷)锟斤拷锟斤拷要锟截ｏ拷锟斤拷锟絰锟斤拷锟斤拷锟斤拷(du锟斤拷)锟斤拷(y锟斤拷ng)锟絇(gu锟斤拷n)系锟斤拷值锟斤拷

锟斤拷锟斤拷锟斤拷注锟解：(1)锟斤拷(g锟斤拷u)锟缴猴拷锟斤拷(sh锟斤拷)锟斤拷锟斤拷(g锟斤拷)要锟斤拷锟角讹拷锟絰锟斤拷锟斤拷锟斤拷(du锟斤拷)锟斤拷(y锟斤拷ng)锟絇(gu锟斤拷n)系锟斤拷值锟斤拷.锟斤拷锟斤拷值锟斤拷锟斤拷锟缴讹拷锟絰锟斤拷蛯锟�(du锟斤拷)锟斤拷(y锟斤拷ng)锟絇(gu锟斤拷n)系锟絈锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷蓚锟�(g锟斤拷)锟斤拷锟斤拷(sh锟斤拷)锟侥讹拷锟絰锟斤拷蛯锟�(du锟斤拷)锟斤拷(y锟斤拷ng)锟絇(gu锟斤拷n)系锟斤拷全一锟铰ｏ拷锟斤拷锟絈锟紷锟缴傦拷(g锟斤拷)锟斤拷锟斤拷(sh锟斤拷)锟斤拷锟�(锟斤拷?y锟斤拷n)锟酵�一锟斤拷锟�?sh锟斤拷))(2)锟缴傦拷(g锟斤拷)锟斤拷锟斤拷(sh锟斤拷)锟斤拷犬锟�(d锟斤拷ng)锟揭僅锟斤拷(d锟斤拷ng)锟斤拷锟斤拷锟侥讹拷锟絰锟斤拷蛯锟�(du锟斤拷)锟斤拷(y锟斤拷ng)锟絇(gu锟斤拷n)系锟斤拷全一锟斤拷锟斤拷锟斤拷锟絚锟斤拷示锟斤拷變锟斤拷锟酵猴拷锟斤拷(sh锟斤拷)值锟斤拷锟斤拷母锟給(w锟斤拷)锟絇(gu锟斤拷n)锟斤拷锟斤拷同锟斤拷锟斤拷(sh锟斤拷)锟斤拷锟叫斷方锟斤拷锟斤拷锟劫憋拷锟絖(d锟斤拷)式锟斤拷同;锟节讹拷锟絰锟斤拷一锟斤拷(锟斤拷锟絚(di锟斤拷n)锟斤拷锟酵�锟絩(sh锟斤拷)锟竭傦拷)

锟斤拷锟斤拷(見锟絥锟斤拷21锟�(y锟斤拷)锟斤拷锟絇(gu锟斤拷n)锟斤拷2)

锟斤拷锟斤拷值锟斤拷锟絘(b锟斤拷)锟斤拷

锟斤拷锟斤拷(1)锟斤拷锟斤拷锟斤拷(sh锟斤拷)锟斤拷值锟斤拷取锟絈锟节讹拷锟絰锟斤拷蛯锟�(du锟斤拷)锟斤拷(y锟斤拷ng)锟斤拷锟絫锟斤拷锟斤拷論锟斤拷取什么锟斤拷锟斤拷锟襟函旓拷(sh锟斤拷)锟斤拷值锟津都戯拷(y锟斤拷ng)锟饺匡拷锟絔锟戒定锟絰锟斤拷.(2).锟斤拷(y锟斤拷ng)锟斤拷悉锟斤拷锟斤拷一锟轿猴拷锟斤拷(sh锟斤拷)锟斤拷锟斤拷锟轿猴拷锟斤拷(sh锟斤拷)锟斤拷指锟斤拷(sh锟斤拷)锟斤拷锟斤拷(du锟斤拷)锟斤拷(sh锟斤拷)锟斤拷锟斤拷(sh锟斤拷)锟斤拷锟斤拷锟斤拷锟角猴拷锟斤拷(sh锟斤拷)锟斤拷值锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷(f锟斤拷)锟絪锟斤拷锟斤拷(sh锟斤拷)值锟斤拷幕锟斤拷A(ch锟斤拷)锟斤拷

锟斤拷锟斤拷3.锟斤拷锟斤拷(sh锟斤拷)锟紻锟斤拷知锟絉(sh锟斤拷)锟絯锟絳

锟斤拷锟斤拷(1)锟斤拷锟絰锟斤拷锟斤拷平锟斤拷直锟斤拷锟斤拷锟斤拷(bi锟斤拷o)系锟斤拷锟斤拷锟皆猴拷锟斤拷(sh锟斤拷)y=f(x),(x∈A)锟叫碉拷x锟斤拷M锟斤拷锟斤拷(bi锟斤拷o)锟斤拷锟斤拷锟斤拷(sh锟斤拷)值y锟斤拷v锟斤拷锟斤拷(bi锟斤拷o)锟斤拷锟絚(di锟斤拷n)P(x锟斤拷y)锟侥硷拷锟斤拷C锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷(sh锟斤拷)y=f(x),(x∈A)锟侥圖锟斤拷.

锟斤拷锟斤拷C锟斤拷每一锟絚(di锟斤拷n)锟斤拷锟斤拷锟斤拷(bi锟斤拷o)(x锟斤拷y)锟斤拷锟組锟姐函锟斤拷(sh锟斤拷)锟絇(gu锟斤拷n)系y=f(x)锟斤拷锟斤拷锟絕(gu锟斤拷)锟斤拷(l锟斤拷i)锟斤拷锟皆滿锟斤拷y=f(x)锟斤拷每一锟組锟斤拷锟斤拷?q锟斤拷)锟斤拷?sh锟斤拷)锟斤拷(du锟斤拷)x锟斤拷y锟斤拷锟斤拷锟斤拷(bi锟斤拷o)锟斤拷锟絚(di锟斤拷n)(x锟斤拷y)锟斤拷锟斤拷锟斤拷C锟斤拷.锟斤拷記锟斤拷C={P(x,y)|y=f(x),x∈A}

锟斤拷锟斤拷锟紻锟斤拷C一锟斤拷锟斤拷锟揭伙拷l锟解滑锟斤拷锟紹锟絤(x锟斤拷)锟斤拷锟斤拷(锟斤拷直锟斤拷),也锟斤拷锟斤拷锟斤拷锟斤拷锟絚锟斤拷锟斤拷平锟斤拷锟絚Y锟絊锟斤拷直锟斤拷锟斤拷锟街伙拷锟揭伙拷锟�(g锟斤拷)锟斤拷锟絚(di锟斤拷n)锟斤拷锟斤拷锟缴條锟斤拷锟斤拷锟斤拷锟絰散锟絚(di锟斤拷n)锟組锟斤拷锟斤拷

锟斤拷锟斤拷(2)锟斤拷锟斤拷

锟斤拷锟斤拷A锟斤拷锟斤拷锟絚(di锟斤拷n)锟斤拷锟斤拷锟斤拷锟斤拷(j锟斤拷)锟斤拷锟斤拷(sh锟斤拷)锟斤拷锟斤拷式锟酵讹拷锟絰锟斤拷锟斤拷锟絰,y锟斤拷一些锟斤拷(du锟斤拷)锟斤拷(y锟斤拷ng)值锟斤拷锟叫憋拷锟斤拷锟斤拷(x,y)锟斤拷锟斤拷锟斤拷(bi锟斤拷o)锟斤拷锟斤拷锟斤拷(bi锟斤拷o)系锟斤拷(n锟斤拷i)锟斤拷锟斤拷锟斤拷锟�(y锟斤拷ng)锟斤拷锟絚(di锟斤拷n)P(x,y)锟斤拷锟斤拷锟斤拷锟狡斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷@些锟絚(di锟斤拷n)锟紹锟斤拷锟斤拷锟斤拷(l锟斤拷i).

锟斤拷锟斤拷B锟斤拷锟紻锟斤拷變锟絈锟斤拷(請(q锟斤拷ng)锟斤拷锟斤拷锟斤拷锟斤拷4锟斤拷锟角猴拷锟斤拷(sh锟斤拷))

锟斤拷锟斤拷锟斤拷锟斤拷變锟絈锟斤拷锟斤拷锟斤拷锟斤拷锟絅锟斤拷锟斤拷平锟斤拷變锟絈锟斤拷锟斤拷s變锟絈锟酵岋拷(du锟斤拷)锟絈變锟絈

锟斤拷锟斤拷(3)锟斤拷锟矫ｏ拷

锟斤拷锟斤拷1锟斤拷直锟絕锟侥匡拷锟斤拷锟斤拷锟斤拷(sh锟斤拷)锟斤拷锟斤拷锟絴(zh锟斤拷);2锟斤拷锟斤拷锟矫旓拷(sh锟斤拷)锟轿結(ji锟斤拷)锟较的凤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絵锟斤拷思路锟斤拷锟斤拷呓锟斤拷}锟斤拷锟劫度★拷

锟斤拷锟斤拷锟絣(f锟斤拷)锟紽(xi锟斤拷n)锟斤拷锟絵锟叫碉拷锟絜(cu锟斤拷)锟絗锟斤拷

锟斤拷锟斤拷4.锟斤拷去锟剿斤拷^(q锟斤拷)锟絞锟侥革拷锟斤拷

锟斤拷锟斤拷(1)锟絕(q锟斤拷)锟絞锟侥凤拷類ｏ拷锟絖锟絕(q锟斤拷)锟絞锟斤拷锟絔锟絕(q锟斤拷)锟絞锟斤拷锟斤拷锟絖锟斤拷锟絔锟絕(q锟斤拷)锟絞;(2)锟給(w锟斤拷)锟紽锟絕(q锟斤拷)锟絞;(3)锟絕(q锟斤拷)锟絞锟侥旓拷(sh锟斤拷)锟絊锟斤拷示.

锟斤拷锟斤拷5.什么锟斤拷锟斤拷映锟斤拷

锟斤拷锟斤拷一锟斤拷锟�锟斤拷锟絆(sh锟斤拷)A锟斤拷B锟角兩傦拷(g锟斤拷)锟角空的硷拷锟斤拷锟斤拷锟斤拷锟斤拷锟侥骋伙拷锟�(g锟斤拷)锟絖锟斤拷锟侥岋拷(du锟斤拷)锟斤拷(y锟斤拷ng)锟斤拷锟絫f锟斤拷使锟斤拷(du锟斤拷)锟节硷拷锟斤拷A锟叫碉拷锟斤拷锟斤拷一锟斤拷(g锟斤拷)元锟斤拷x锟斤拷锟节硷拷锟斤拷B锟叫讹拷锟斤拷唯一锟絖锟斤拷锟斤拷元锟斤拷y锟絚之锟斤拷(du锟斤拷)锟斤拷(y锟斤拷ng)锟斤拷锟斤拷么锟酵稱锟斤拷(du锟斤拷)锟斤拷(y锟斤拷ng)f锟斤拷AB锟斤拷募锟斤拷锟紸锟斤拷锟斤拷锟斤拷B锟斤拷一锟斤拷(g锟斤拷)映锟斤拷锟斤拷記锟斤拷“f锟斤拷AB”

锟斤拷锟斤拷锟給锟斤拷一锟斤拷(g锟斤拷)锟斤拷锟斤拷A锟斤拷B锟斤拷映锟斤拷锟斤拷锟斤拷锟絘∈A,b∈B.锟斤拷元锟斤拷a锟斤拷元锟斤拷b锟斤拷(du锟斤拷)锟斤拷(y锟斤拷ng)锟斤拷锟斤拷么锟斤拷锟揭傦拷锟斤拷元锟斤拷b锟斤拷锟斤拷元锟斤拷a锟斤拷锟斤拷锟斤拷元锟斤拷a锟斤拷锟斤拷元锟斤拷b锟斤拷原锟斤拷

锟斤拷锟斤拷锟絝(shu锟斤拷)锟斤拷锟斤拷锟斤拷锟斤拷(sh锟斤拷)锟斤拷一锟絅锟斤拷锟斤拷锟接筹拷洌�映锟斤拷锟斤拷一锟絅锟斤拷锟斤拷膶锟�(du锟斤拷)锟斤拷(y锟斤拷ng)锟斤拷锟劫硷拷锟斤拷A锟斤拷B锟斤拷锟斤拷(du锟斤拷)锟斤拷(y锟斤拷ng)锟斤拷锟絫f锟角確锟斤拷锟斤拷;锟节岋拷(du锟斤拷)锟斤拷(y锟斤拷ng)锟斤拷锟絫锟斤拷“锟斤拷锟斤拷锟斤拷”锟斤拷锟斤拷锟斤拷(qi锟斤拷ng)锟絳(di锟斤拷o)锟侥硷拷锟斤拷A锟斤拷锟斤拷锟斤拷B锟侥岋拷(du锟斤拷)锟斤拷(y锟斤拷ng)锟斤拷锟斤拷锟絚锟斤拷B锟斤拷A锟侥岋拷(du锟斤拷)锟斤拷(y锟斤拷ng)锟絇(gu锟斤拷n)系一锟斤拷锟角诧拷同锟斤拷;锟桔岋拷(du锟斤拷)锟斤拷映锟斤拷f锟斤拷A→B锟斤拷(l锟斤拷i)锟絝(shu锟斤拷)锟斤拷锟絫锟斤拷(y锟斤拷ng)锟組锟姐：(锟斤拷)锟斤拷锟斤拷A锟叫碉拷每一锟斤拷(g锟斤拷)元锟斤拷锟斤拷锟节硷拷锟斤拷B锟叫讹拷锟斤拷锟襟，诧拷锟斤拷锟斤拷锟斤拷唯一锟斤拷;(锟斤拷)锟斤拷锟斤拷A锟叫诧拷同锟斤拷元锟斤拷锟斤拷锟节硷拷锟斤拷B锟叫岋拷(du锟斤拷)锟斤拷(y锟斤拷ng)锟斤拷锟斤拷锟斤拷锟斤拷锟酵�一锟斤拷(g锟斤拷);(锟斤拷)锟斤拷要锟襟集猴拷B锟叫碉拷每一锟斤拷(g锟斤拷)元锟斤拷锟节硷拷锟斤拷A锟叫讹拷锟斤拷原锟斤拷

锟斤拷锟絇(gu锟斤拷n)锟斤拷锟絔锟斤拷

锟斤拷锟斤拷锟竭匡拷锟斤拷(sh锟斤拷)锟絎(xu锟斤拷)知锟絉(sh锟斤拷)锟絚(di锟斤拷n)锟絉锟斤拷

锟斤拷锟铰高匡拷锟結訊锟斤拷锟竭匡拷锟斤拷锟斤拷锟斤拷锟斤拷前锟斤拷(zh锟斤拷n)锟戒、志愿锟斤拷锟�(b锟斤拷o)锟斤拷锟饺★拷锟�?j锟斤拷n)?sh锟斤拷)锟斤拷锟斤拷

锟竭匡拷锟絩(sh锟斤拷)锟絞锟斤拷锟斤拷全锟斤拷锟斤拷要锟斤拷(ji锟斤拷)锟絚(di锟斤拷n)

锟組锟斤拷"锟竭匡拷锟絎(w锟斤拷ng)"微锟脚癸拷锟斤拷號(h锟斤拷o)