![](https://static.youtibao.com/asksite/comm/h5/images/m_q_title.png)
[单选题]
已知|x|=3,(y+1)^2=4,且xy<0,则x-y的值是()
A.4或-6
B.-4或6
C.7或6或1或0
D.-7或-6或-1或0
![](https://static.youtibao.com/asksite/comm/h5/images/m_q_a.png)
B、-4或6
![](https://static.youtibao.com/asksite/comm/h5/images/solist_ts.png)
A.4或-6
B.-4或6
C.7或6或1或0
D.-7或-6或-1或0
B、-4或6
下列命题是真命题的是() (A)3>2且-1<0 (B)若A ∩ B=Φ,则A=Φ (C)方程(x-1)2+(y+1)2=0的解是x=1或y=-1 (D)存在x∈R,使x2=-1
已知y=f(x)(x∈R)是以4为周期的奇函数,且f(l)=1,f(3)=a,则有
A.a=1
B.a=2
C.a=-1
D.a=-2
已知向量a=(4,x),向量b=(5,-2),且a⊥b,则x等于()
A.10
B.-10
C.1/10
D.-8/5
已知二次函数f(x)=ax2+bx+c的图像关于x=1对称,且f(1)=4,f(0)=3.
(I)求二次函数的解析式;
(1I)若,(x)>3,求对应x的取值范围.
已知函数f(x)=㏒2(ax+b),若f(2)=2,f(3)=3,则() (A)a=1,b=-4 (B)a=2,b=-2 (C)a=4,b=3 (D)a=4,b=-4
已知函数f(x)=10g2(2x+m)的定义域为[2,+∞),则f(10)等于() (A)3+log23 (B)1+2log23 (C)3 (D)4
已知f(x)是定义域在[-5,5]上的偶函数,且f(3)>f(1)则下列各式一定成立的是
A.f(-1)<f(3)
B.f(0)<f(5)
C.f(3)>f(2)
D.f(2)>f(0)