已知平面向量a=(1，t)，b=(-1，2)，若a+b行于向量(-2，1)，则(　　)

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设函数ƒ(x+2)=2x-2-5，则ƒ(4)=（）

A -5 B -4 C 3 D 1

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过点(2,-2)且与双曲线x2-2y2=2有公共渐近线的双曲线方程是（）

A <img width="113" height="40" src="https://www.beizhujiaoyu.com/uploads/202208/20190918212137_5578.png" /> B <img width="92" height="39" src="https://www.beizhujiaoyu.com/uploads/202208/20190918212139_5422.png" /> C <img width="111" height="38" src="https://www.beizhujiaoyu.com/uploads/202208/20190918212139_7141.png" /> D <img width="235" height="40" src="https://www.beizhujiaoyu.com/uploads/202208/20190918212141_6984.png" />

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下列（）成立．

A 0．760.12<1 B <img width="93" height="38" src="https://www.beizhujiaoyu.com/uploads/202208/20190918212127_5131.png" /> C loga(a+1)<log(a+1)a D 20.32<20.31

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（）

A <img width="78" height="20" src="https://www.beizhujiaoyu.com/uploads/202208/20190918212120_7609.png" /> B <img width="84" height="19" src="https://www.beizhujiaoyu.com/uploads/202208/20190918212120_9484.png" /> C <img width="48" height="15" src="https://www.beizhujiaoyu.com/uploads/202208/20190918212122_8859.png" /> D <img width="48" height="15" src="https://www.beizhujiaoyu.com/uploads/202208/20190918212123_1203.png" />

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根据连续函数的定义，下列函数在指定点或开区间上不连续的是（）

A ƒ(x)=2x+1，点x=-1 B ƒ(x)=ax2+bx+C，点x=0 C <img width="302" height="45" src="https://www.beizhujiaoyu.com/uploads/202208/20190918212141_9184.png" /> D <img width="234" height="38" src="https://www.beizhujiaoyu.com/uploads/202208/20190918212143_8703.png" />

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若1名女生和3名男生排成一排，则该女生不在两端的不同排法共有( )

A 24种 B 12种 C 16种 D 8种

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圆x2+y2+2x-6y-6=0的半径为( )

A <img width="38" height="21" src="https://www.beizhujiaoyu.com/uploads/202208/20190918212842_5405.png" > B 4 C <img width="39" height="21" src="https://www.beizhujiaoyu.com/uploads/202208/20190918212844_5405.png" > D 16

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函数y=2x的图像与直线x+3=0的交点坐标为( )

A <img width="107" height="39" src="https://www.beizhujiaoyu.com/uploads/202208/20190918212751_1190.png" > B <img width="81" height="39" src="https://www.beizhujiaoyu.com/uploads/202208/20190918212753_0877.png" > C <img width="81" height="39" src="https://www.beizhujiaoyu.com/uploads/202208/20190918212753_2908.png" > D <img width="107" height="39" src="https://www.beizhujiaoyu.com/uploads/202208/20190918212755_3377.png" >

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函数y=log2(x+2)的图像向上平移1个单位后，所得图像对应的函数为( )

A y=log2(x+1) B y=log2(x+3) C y=log2(x+2)-1 D y=log2(x+2)+1

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( )

A {x｜x≥0} B {x｜x≥1} C {x｜0≤x≤1} D {x｜x≤0或x≥1}

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已知平面向量a=(1，t)，b=(-1，2)，若a+b行于向量(-2，1)，则(　　)

A 2t-3m+1=0

B 2t+3m+1=0

C 2t-3m-1=0

D 2t+3m-1=0

相关试题

已知平面向量a=(1，t)，b=(-1，2)，若a+b行于向量(-2，1)，则( )

A 2t-3m+1=0 B 2t+3m+1=0 C 2t-3m-1=0 D 2t+3m-1=0

相关试题

已知平面向量a=(1，t)，b=(-1，2)，若a+b行于向量(-2，1)，则(　　)

A 2t-3m+1=0

B 2t+3m+1=0

C 2t-3m-1=0

D 2t+3m-1=0