锟斤拷锟斤拷一.锟絕锟届法

锟斤拷锟斤拷通锟絕(gu锟斤拷)锟斤拷(du锟斤拷)锟斤拷锟斤拷(sh锟斤拷)锟斤拷锟絰锟斤拷锟斤拷锟斤拷锟絴(zh锟斤拷)锟斤拷锟絕锟届，锟結(ji锟斤拷)锟较猴拷锟斤拷(sh锟斤拷)锟侥斤拷锟斤拷式锟斤拷锟斤拷煤锟斤拷锟�(sh锟斤拷)锟斤拷值锟斤拷锟斤拷

锟斤拷锟斤拷锟斤拷1锟襟函旓拷(sh锟斤拷)y=3+√(2-3x) 锟斤拷值锟斤拷

锟斤拷锟斤拷锟絚(di锟斤拷n)锟杰ｏ拷锟斤拷锟斤拷(j锟斤拷)锟斤拷锟絞(sh锟斤拷)平锟斤拷锟斤拷锟斤拷锟斤拷锟絴(zh锟斤拷)锟斤拷锟斤拷锟斤拷锟�√(2-3x) 锟斤拷值锟斤拷

锟斤拷锟斤拷锟解：锟斤拷锟斤拷锟絞(sh锟斤拷)平锟斤拷锟斤拷锟斤拷锟斤拷锟絴(zh锟斤拷)锟斤拷知√(2-3x)≥0锟斤拷

锟斤拷锟斤拷锟斤拷锟絵通锟絕(gu锟斤拷)直锟斤拷锟絕锟斤拷锟斤拷锟絞(sh锟斤拷)平锟斤拷锟斤拷锟斤拷锟斤拷锟絴(zh锟斤拷)锟斤拷锟紷锟解，锟紷锟絅锟斤拷锟斤拷锟斤拷(du锟斤拷)锟斤拷一類猴拷锟斤拷(sh锟斤拷)锟斤拷值锟斤拷锟斤拷锟�锟斤拷锟斤拷(ji锟斤拷n)锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷失锟斤拷一锟絅锟缴凤拷锟斤拷

锟斤拷锟斤拷锟襟函旓拷(sh锟斤拷)y=[x](0≤x≤5)锟斤拷值锟斤拷锟斤拷(锟金案ｏ拷值锟斤拷?y锟斤拷n)椋簕0锟斤拷1锟斤拷2锟斤拷3锟斤拷4锟斤拷5锟斤拷)

锟斤拷锟斤拷锟斤拷.锟斤拷锟斤拷锟斤拷(sh锟斤拷)锟斤拷

锟斤拷锟斤拷锟斤拷(d锟斤拷ng)锟斤拷锟斤拷(sh锟斤拷)锟侥凤拷锟斤拷锟斤拷(sh锟斤拷)锟斤拷锟节時(sh锟斤拷)锟斤拷锟絫锟戒反锟斤拷锟斤拷(sh锟斤拷)锟侥讹拷锟絰锟斤拷锟斤拷锟皆�锟斤拷锟斤拷(sh锟斤拷)锟斤拷值锟斤拷锟斤拷

锟斤拷锟斤拷锟斤拷2锟襟函旓拷(sh锟斤拷)y=(x+1)/(x+2)锟斤拷值锟斤拷

锟斤拷锟斤拷锟絚(di锟斤拷n)锟杰ｏ拷锟斤拷锟斤拷锟皆�锟斤拷锟斤拷(sh锟斤拷)锟侥凤拷锟斤拷锟斤拷(sh锟斤拷)锟斤拷锟斤拷锟斤拷锟斤拷涠�锟絰锟斤拷锟斤拷

锟斤拷锟斤拷锟解：锟紷然锟斤拷锟斤拷(sh锟斤拷)y=(x+1)/(x+2)锟侥凤拷锟斤拷锟斤拷(sh锟斤拷)锟斤拷:x=(1-2y)/(y-1),锟戒定锟絰锟斤拷?y锟斤拷n)锟統≠1锟侥岋拷(sh锟斤拷)锟斤拷(sh锟斤拷),锟绞猴拷锟斤拷(sh锟斤拷)y锟斤拷值锟斤拷?y锟斤拷n)锟絳y?y≠1,y∈R锟斤拷锟斤拷

锟斤拷锟斤拷锟襟函旓拷(sh锟斤拷)y=(10x+10-x)/(10x-10-x)锟斤拷值锟斤拷锟斤拷(锟金案ｏ拷锟斤拷锟斤拷(sh锟斤拷)锟斤拷值锟斤拷?y锟斤拷n)锟絳y?y<-1 y="">1锟斤拷)

锟斤拷锟斤拷锟斤拷.锟戒方锟斤拷

锟斤拷锟斤拷锟斤拷(d锟斤拷ng)锟斤拷锟給锟斤拷锟斤拷(sh锟斤拷)锟角讹拷锟轿猴拷锟斤拷(sh锟斤拷)锟斤拷苫锟斤拷锟斤拷锟轿猴拷锟斤拷(sh锟斤拷)锟侥忥拷(f锟斤拷)锟较猴拷锟斤拷(sh锟斤拷)锟絩(sh锟斤拷),锟斤拷锟斤拷锟斤拷锟斤拷锟戒方锟斤拷锟襟函旓拷(sh锟斤拷)值锟斤拷

锟斤拷锟斤拷锟斤拷3锟斤拷锟襟函旓拷(sh锟斤拷)y=√(-x2+x+2)锟斤拷值锟斤拷锟斤拷

锟斤拷锟斤拷锟絚(di锟斤拷n)锟杰ｏ拷锟斤拷锟斤拷锟絖锟斤拷锟斤拷(sh锟斤拷)锟戒方锟斤拷锟斤拷全平锟斤拷锟斤拷(sh锟斤拷)锟斤拷锟斤拷锟矫讹拷锟轿猴拷锟斤拷(sh锟斤拷)锟斤拷锟斤拷值锟斤拷锟斤拷

锟斤拷锟斤拷锟解：锟斤拷-x2+x+2≥0,锟斤拷知锟斤拷锟斤拷(sh锟斤拷)锟侥讹拷锟絰锟斤拷?y锟斤拷n)锟絰∈[-1锟斤拷2]锟斤拷锟剿時(sh锟斤拷)-x2+x+2=-(x-1/2)2+9/4∈[0锟斤拷9/4]

锟斤拷锟斤拷锟襟函旓拷(sh锟斤拷)y=2x-5+√15-4x锟斤拷值锟斤拷.(锟斤拷:值锟斤拷?y锟斤拷n)锟絳y?y≤3})

锟斤拷锟斤拷锟斤拷.锟叫別式锟斤拷

锟斤拷锟斤拷锟斤拷锟缴伙拷锟斤拷锟絇(gu锟斤拷n)锟斤拷某變锟斤拷锟侥讹拷锟轿凤拷锟教的凤拷式锟斤拷锟斤拷(sh锟斤拷)锟斤拷o(w锟斤拷)锟斤拷锟斤拷锟斤拷(sh锟斤拷),锟斤拷锟斤拷锟叫別式锟斤拷锟襟函旓拷(sh锟斤拷)锟斤拷值锟斤拷

锟斤拷锟斤拷锟斤拷4锟襟函旓拷(sh锟斤拷)y=(2x2-2x+3)/(x2-x+1)锟斤拷值锟斤拷锟斤拷

锟斤拷锟斤拷锟絚(di锟斤拷n)锟杰ｏ拷锟斤拷原锟斤拷锟斤拷(sh锟斤拷)锟紻(zhu锟斤拷n)锟斤拷锟斤拷锟斤拷變锟斤拷锟侥讹拷锟轿凤拷锟斤拷锟斤拷锟斤拷(y锟斤拷ng)锟矫讹拷锟轿凤拷锟教革拷锟斤拷锟叫別式锟斤拷锟侥讹拷锟絖锟斤拷锟斤拷原锟斤拷锟斤拷(sh锟斤拷)锟斤拷值锟斤拷锟斤拷

锟斤拷锟斤拷锟解：锟斤拷锟斤拷式锟斤拷锟斤拷(y-2)x2-(y-2)x+(y-3)=0 (*)

锟斤拷锟斤拷锟斤拷(d锟斤拷ng)y≠2锟絩(sh锟斤拷),锟斤拷Δ=(y-2)2-4(y-2)x+(y-3)≥0锟斤拷锟斤拷茫锟�2

锟斤拷锟斤拷锟襟函旓拷(sh锟斤拷)y=1/(2x2-3x+1)锟斤拷值锟斤拷锟斤拷(锟金案ｏ拷值锟斤拷?y锟斤拷n)锟統≤-8锟斤拷y>0)锟斤拷

锟斤拷锟斤拷锟斤拷.锟斤拷值锟斤拷

锟斤拷锟斤拷锟斤拷(du锟斤拷)锟斤拷锟絔锟絕(q锟斤拷)锟絞[a,b]锟较碉拷锟紹锟絤(x锟斤拷)锟斤拷锟斤拷(sh锟斤拷)y=f(x),锟斤拷锟斤拷锟統=f(x)锟节區(q锟斤拷)锟絞[a,b]锟斤拷(n锟斤拷i)锟侥極值,锟斤拷锟絚邊锟斤拷值f(a).f(b)锟斤拷锟斤拷锟絕,锟斤拷锟斤拷锟斤拷锟�(sh锟斤拷)锟斤拷锟斤拷值,锟缴得碉拷锟斤拷锟斤拷(sh锟斤拷)y锟斤拷值锟斤拷锟斤拷

锟斤拷锟斤拷锟斤拷5锟斤拷知(2x2-x-3)/(3x2+x+1)≤0,锟揭滿锟斤拷x+y=1,锟襟函旓拷(sh锟斤拷)z=xy+3x锟斤拷值锟斤拷锟斤拷

锟斤拷锟斤拷锟絚(di锟斤拷n)锟杰ｏ拷锟斤拷锟斤拷(j锟斤拷)锟斤拷知锟絣锟斤拷锟斤拷锟斤拷锟阶冿拷锟絰锟斤拷取值锟斤拷锟斤拷锟斤拷锟斤拷目锟斤拷(bi锟斤拷o)锟斤拷锟斤拷(sh锟斤拷)锟斤拷元锟斤拷锟戒方锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟�(sh锟斤拷)锟斤拷值锟斤拷锟斤拷

锟斤拷锟斤拷锟解：锟斤拷3x2+x+1>0锟斤拷锟斤拷锟斤拷锟斤拷式锟斤拷锟斤拷式锟絚锟斤拷锟斤拷式2x2-x-3≤0同锟解，锟斤拷之锟斤拷-1≤x≤3/2锟斤拷锟斤拷x+y=1锟斤拷锟斤拷y=1-x锟斤拷锟斤拷z=xy+3x锟斤拷锟斤拷锟斤拷z=-x2+4x(-1≤x≤3/2),

锟斤拷锟斤拷∴z=-(x-2)2+4锟斤拷x∈[-1,3/2],锟斤拷锟斤拷(sh锟斤拷)z锟节區(q锟斤拷)锟絞[-1,3/2]锟斤拷锟紹锟絤(x锟斤拷)锟斤拷锟斤拷只锟斤拷锟斤拷^邊锟斤拷拇锟叫�锟斤拷

锟斤拷锟斤拷锟斤拷(d锟斤拷ng)x=-1锟絩(sh锟斤拷)锟斤拷z=-5;锟斤拷(d锟斤拷ng)x=3/2锟絩(sh锟斤拷)锟斤拷z=15/4锟斤拷

锟斤拷锟斤拷锟斤拷√x锟介實(sh锟斤拷)锟斤拷(sh锟斤拷)锟斤拷锟絫锟斤拷锟斤拷(sh锟斤拷)y=x2+3x-5锟斤拷值锟斤拷?y锟斤拷n)?( )

锟斤拷锟斤拷A.(-∞锟斤拷+∞) B.[-7锟斤拷+∞] C.[0锟斤拷+∞) D.[-5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)锟斤拷锟斤拷锟竭匡拷锟紸(y锟斤拷)锟統(c锟斤拷)锟斤拷志愿锟斤拷锟�(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)

锟斤拷锟斤拷锟組锟斤拷"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)