一選
1.()式(a-2)x2+2(a-2)x-4<0一xRa取值圍( )
A.(-,2 B. -2,2 C.(-2,2 D.(-,-2)
2.()魏f(x)=x2-x+a(a>0),f(m)<0,f(m-1)值為( )
A. B.
C.歉 D.愣夾?/p>
3.()知魏f(x)=4x2-2(p-2)x-2p2-p+1,[-11]俅一實(shí)c,使f(c)>0,實(shí)p取值圍_________.
4.()魏f(x)畝系為葉實(shí)xf(2+x)=f(2-x),f(1-2x2)
5.()知實(shí)t系式 (a>0a1)
(1)t=ax,y=f(x)謀式;
(2)x(0,2 時(shí)y小值8ax值.
6.()魏y=mx2+(m-3)x+1圖x慕一原也�，m取值圍.
7.()魏f(x)=px2+qx+r實(shí)pqr =0,m>0,證
(1)pf( )<0;
(2)f(x)=0(01)諍薪.
8.()一小裝某址攏x()奐P(元/)之墓系為P=160-2x,x某殺R=500+30x元.
(1)貿(mào)虜時(shí)祿玫1300元?
(2)虜為時(shí)苫?嵌元?
慰
訓(xùn)懦
猓褐?,(-4a)2-4(2a+12)0,- a2
(1)- a<1時(shí)原袒為x=-a2+a+6,-a2+a+6=-(a- )2+ .
a=- 時(shí)xmin= ,a= 時(shí)xmax= .
x .
(2)1a2時(shí)x=a2+3a+2=(a+ )2- 嗟盿=1時(shí)xmin=6,a=2時(shí)xmax=12,6x12.
, x12.
訓(xùn)訓(xùn)
一1.a-2=0a=2時(shí),式為-4<0,.a=2,a-20時(shí)a ,-2
鳶福C
2.f(x)=x2-x+a畝猿為x= ,f(1)>0,f(0)>0,f(m)<0,m(0,1),
m-1<0,f(m-1)>0.
鳶福A
3.只f(1)=-2p2-3p+9>0f(-1)=-2p2+p+1>0-3
鳶福(-3 )
4.f(2+x)=f(2-x)知x=2為猿�，隈x誠(chéng)僥敵?/p>
|1-2x2-2|<|1+2x-x2-2|,-2
鳶福-2
5.猓?1)loga logat-3=logty-3logta
t=ax知x=logat式x-3= ,
logay=x2-3x+3y=a (x0).
(2)u=x2-3x+3=(x- )2+ (x0),y=au
0
u=(x- )2+ (02 應(yīng)值u(02 喜值.
a>1,要使y=au小值8u=(x- )2+ ,x(0,2 應(yīng)小值
嗟眡= 時(shí)umin= ,ymin= =8a=16.a=16,x= .
6.猓篺(0)=1>0
(1)m<0時(shí)魏圖x曳直y啵?
(2)m>0時(shí) 0
m取值圍{m|m1m0}.
7.證(1) ,f(x)嵌魏p0,m>0,裕pf( )<0.
(2)猓琭(0)=r,f(1)=p+q+r
俚p<0時(shí)(1)知f( )<0
r>0,f(0)>0,f( )<0,f(x)=0(0 )薪;
r0,f(1)=p+q+r=p+(m+1)=(- )+r= >0,
f( )<0,f(x)=0( ,1)薪.
詰p<0時(shí)同證.
8.猓?1)貿(mào)祿為y,錨
y=(160-2x)x-(500+30x)=-2x2+130x-500
y1300知-2x2+130x-5001300
x2-65x+9000(x-20)(x-45)020x45
嗟甭?0~45之時(shí)祿1300元.
(2)(1)知y=-2x2+130x-500=-2(x- )2+1612.5
x為x=3233時(shí)y取值為1612元
嗟甭參?233時(shí)苫1612元.
2017煽猓?/strong>2017爍嚦史憑學(xué)模
2017煽2017爍嚦時(shí)/
